eprover

Langue: en

Version: 330075 (ubuntu - 24/10/10)

Section: 1 (Commandes utilisateur)

NAME

E - The Equational Theorem Prover User Manual

SYNOPSIS

eprover [options] [files]
eproof [options] [files]

DESCRIPTION

E 1.0-004 "Temi"

eprover reads a set of first-order clauses and formulae and tries to refute it.

eproof is a wrapper script that calls eprover and then runs epclextract on its output to construct a proof.

-h
--help
Print a short description of program usage and options.
-V
--version
Print the version number of the prover. Please include this with all bug reports (if any).
-v
--verbose[=<arg>]
Verbose comments on the progress of the program. This differs from the output level (below) in that technical information is printed to stderr, while the output level determines which logical manipulations of the clauses are printed to stdout. The short form or the long form without the optional argument is equivalent to --verbose=1.
-o <arg>
--output-file=<arg>
Redirect output into the named file.
-s
--silent
Equivalent to --output-level=0.
-l <arg>
--output-level=<arg>
Select an output level, greater values imply more verbose output. Level 0 produces nearly no output, level 1 will output each clause as it is processed, level 2 will output generating inferences, level 3 will give a full protocol including rewrite steps and level 4 will include some internal clause renamings. Levels >= 2 also imply PCL2 or TSTP formats (which can be post-processed with suitable tools).
--pcl-terms-compressed
Print terms in the PCL output in shared representation.
--pcl-compact
Print PCL steps without additional spaces for formatting (safes disk space for large protocols).
--print-statistics
Print the inference statistics (only relevant for output level 0, otherwise they are printed automatically.
--print-detailed-statistics
Print data about the proof state that is potentially expensive to collect. Includes number of term cells and number of rewrite steps.
-S
--print-saturated[=<arg>]
Print the (semi-) saturated clause sets after terminating the saturation process. The argument given describes which parts should be printed in which order. Legal characters are 'eigEIGaA', standing for processed positive units, processed negative units, processed non-units, unprocessed positive units, unprocessed negative units, unprocessed non-units, and two types of additional equality axioms, respectively. Equality axioms will only be printed if the original specification contained real equality. In this case, 'a' requests axioms in which a separate substitutivity axiom is given for each argument position of a function or predicate symbol, while 'A' requests a single substitutivity axiom (covering all positions) for each symbol. The short form or the long form without the optional argument is equivalent to --print-saturated=eigEIG.
--print-sat-info
Print additional information (clause number, weight, etc) as a comment for clauses from the semi-saturated end system.
--filter-saturated[=<arg>]
Filter the (semi-) saturated clause sets after terminating the saturation process. The argument is a string describing which operations to take (and in which order). Options are 'u' (remove all clauses with more than one literal), 'c' (delete all but one copy of identical clauses, 'n', 'r', 'f' (forward contraction, unit-subsumption only, no rewriting, rewriting with rules only, full rewriting, respectively), and 'N', 'R' and 'F' (as their lower case counterparts, but with non-unit-subsumption enabled as well). The option without the optional argument is equivalent to --filter-saturated=Fc.
--cnf
Convert the input problem into clause normal form and print it. This is (nearly) equivalent to '--print-saturated=eigEIG --processed-clauses-limit=0' and will by default perform some usually useful simplifications. You can additionally specify e.g. '--no-preprocessing' if you want just the result of CNF translation.
--print-pid
Print the process id of the prover as a comment after option processing.
--error-on-empty
Return with an error code if the input file contains no clauses. Formally, the empty clause set (as an empty conjunction of clauses) is trivially satisfiable, and E will treat any empty input set as satisfiable. However, in composite systems this is more often a sign that something went wrong. Use this option to catch such bugs.
-m <arg>
--memory-limit=<arg>
Limit the memory the prover may use. The argument is the allowed amount of memory in MB. If you use the argument 'Auto', the system will try to figure out the amount of physical memory of your machine and claim most of it. This option may not work everywhere, due to broken and/or strange behaviour of setrlimit() in some UNIX implementations, and due to the fact that I know of no portable way to figure out the physical memory in a machine. Both the option and the 'Auto' version do work under all tested versions of Solaris and GNU/Linux. Due to problems with limit datatypes, it is currently impossible to set a limit of more than 2 GB (2048 MB).
--cpu-limit[=<arg>]
Limit the cpu time the prover should run. The optional argument is the CPU time in seconds. The prover will terminate immediately after reaching the time limit, regardless of internal state. This option may not work everywhere, due to broken and/or strange behaviour of setrlimit() in some UNIX implementations. It does work under all tested versions of Solaris, HP-UX, MacOS-X, and GNU/Linux. As a side effect, this option will inhibit core file writing. Please note that if you use both --cpu-limit and --soft-cpu-limit, the soft limit has to be smaller than the hard limit to have any effect. The option without the optional argument is equivalent to --cpu-limit=300.
--soft-cpu-limit[=<arg>]
Limit the cpu time the prover should spend in the main saturation phase. The prover will then terminate gracefully, i.e. it will perform post-processing, filtering and printing of unprocessed clauses, if these options are selected. Note that for some filtering options (in particular those which perform full subsumption), the postprocessing time may well be larger than the saturation time. This option is particularly useful if you want to use E as a preprocessor or lemma generator in a larger system. The option without the optional argument is equivalent to --soft-cpu-limit=290.
-R
--resources-info
Give some information about the resources used by the prover. You will usually get CPU time information. On systems returning more information with the rusage() system call, you will also get information about memory consumption.
-C <arg>
--processed-clauses-limit=<arg>
Set the maximal number of clauses to process (i.e. the number of traversals of the main-loop).
-P <arg>
--processed-set-limit=<arg>
Set the maximal size of the set of processed clauses. This differs from the previous option in that redundant and back-simplified processed clauses are not counted.
-U <arg>
--unprocessed-limit=<arg>
Set the maximal size of the set of unprocessed clauses. This is a termination condition, not something to use to control the deletion of bad clauses. Compare --delete-bad-limit.
-T <arg>
--total-clause-set-limit=<arg>
Set the maximal size of the set of all clauses. See previous option.
-n
--eqn-no-infix
In LOP, print equations in prefix notation equal(x,y).
-e
--full-equational-rep
In LOP. print all literals as equations, even non-equational ones.
--tptp-in
Parse TPTP-2 format instead of E-LOP (but note that includes are handled according to TPTP-3 semantics).
--tptp-out
Print TPTP format instead of E-LOP. Implies --eqn-no-infix and will ignore --full-equational-rep.
--tptp-format
Equivalent to --tptp-in and --tptp-out.
--tptp2-in
Synonymous with --tptp-in.
--tptp2-out
Synonymous with --tptp-out.
--tptp2-format
Synonymous with --tptp-format.
--tstp-in
Parse TPTP-3 format instead of E-LOP (Note that TPTP-3 syntax is still under development, and the version in E may not be fully conforming at all times. E works on all TPTP 3.0.1 input files (including includes).
--tstp-out
Print output clauses in TPTP-3 syntax. In particular, for output levels >=2, write derivations as TPTP-3 derivations (default is PCL).
--tstp-format
Equivalent to --tstp-in and --tstp-out.
--tptp3-in
Synonymous with --tstp-in.
--tptp3-out
Synonymous with --tstp-out.
--tptp3-format
Synonymous with --tstp-format.
--no-preprocessing
Do not perform preprocessing on the initial clause set. Preprocessing currently removes tautologies and orders terms, literals and clauses in a certain ("canonical") way before anything else happens. Unless the next option is set, it will also unfold equational definitions.
--no-eq-unfolding
During preprocessing, abstain from unfolding (and removing) equational definitions.
--ac-handling[=<arg>]
Select AC handling mode. Preselected is 'DiscardAll', other options are 'None' to disable AC handling, 'KeepUnits', and 'KeepOrientable'. The option without the optional argument is equivalent to --ac-handling=KeepUnits.
--ac-non-aggressive
Do AC resolution on negative literals only on processing (by default, AC resolution is done after clause creation). Only effective if AC handling is not disabled.
-W <arg>
--literal-selection-strategy=<arg>
Choose a strategy for selection of negative literals. There are two special values for this option: NoSelection will select no literal (i.e. perform normal superposition) and NoGeneration will inhibit all generating inferences. For a list of the other (hopefully self-documenting) values run 'eprover -W none'. There are two variants of each strategy. The one prefixed with 'P' will allow paramodulation into maximal positive literals in addition to paramodulation into maximal selected negative literals.
--no-generation
Don't perform any generating inferences (equivalent to --literal-selection-strategy=NoGeneration).
--select-on-processing-only
Perform literal selection at processing time only (i.e. select only in the _given clause_), not before clause evaluation. This is relevant because many clause selection heuristics give special consideration to maximal or selected literals.
-i
--inherit-paramod-literals
Always select the negative literals a previous inference paramodulated into (if possible). If no such literal exists, select as dictated by the selection strategy.
-j
--inherit-goal-pm-literals
In a goal (all negative clause), always select the negative literals a previous inference paramodulated into (if possible). If no such literal exists, select as dictated by the selection strategy.
-j
--inherit-conjecture-pm-literals
In a conjecture-derived clause), always select the negative literals a previous inference paramodulated into (if possible). If no such literal exists, select as dictated by the selection strategy.
--selection-pos-min=<arg>
Set a lower limit for the number of positive literals a clause must have to be eligible for literal selection.
--selection-pos-max=<arg>
Set a upper limit for the number of positive literals a clause can have to be eligible for literal selection.
--selection-neg-min=<arg>
Set a lower limit for the number of negative literals a clause must have to be eligible for literal selection.
--selection-neg-max=<arg>
Set a upper limit for the number of negative literals a clause can have to be eligible for literal selection.
--selection-all-min=<arg>
Set a lower limit for the number of literals a clause must have to be eligible for literal selection.
--selection-all-max=<arg>
Set an upper limit for the number of literals a clause must have to be eligible for literal selection.
--selection-weight-min=<arg>
Set the minimum weight a clause must have to be eligible for literal selection.
--prefer-initial-clauses
Always process all initial clauses first.
-x <arg>
--expert-heuristic=<arg>
Select one of the clause selection heuristics. Currently at least available: Auto, Weight, StandardWeight, RWeight, FIFO, LIFO, Uniq, UseWatchlist. For a full list check HEURISTICS/che_proofcontrol.c. Auto is recommended if you only want to find a proof. It is special in that it will also set some additional options. To have optimal performance, you also should specify -tAuto to select a good term ordering. LIFO is unfair and will make the prover incomplete. Uniq is used internally and is not very useful in most cases. You can define more heuristics using the option -H (see below).
--filter-limit[=<arg>]
Set the limit on the number of 'storage units' in the proof state, after which the set of unprocessed clauses will be filtered against the processed clauses to eliminate redundant clauses. As of E 0.7, a 'storage unit' is approximately one byte, however, storage is estimated in an abstract way, independent of hardware or memory allocation library, and the storage estimate is only an approximation. The option without the optional argument is equivalent to --filter-limit=1000000.
--filter-copies-limit[=<arg>]
Set the number of storage units in new unprocessed clauses after which the set of unprocessed clauses will be filtered for equivalent copies of clauses (see above). As this operation is cheaper, you may want to set this limit lower than --filter-limit. The option without the optional argument is equivalent to --filter-copies-limit=800000.
--delete-bad-limit[=<arg>]
Set the number of storage units after which bad clauses are deleted without further consideration. This causes the prover to be potentially incomplete, but will allow you to limit the maximum amount of memory used fairly well. The prover will tell you if a proof attempt failed due to the incompleteness introduced by this option. It is recommended to set this limit significantly higher than --filter-limit or --filter-copies-limit. If you select -xAuto and set a memory limit, the prover will determine a good value automatically. The option without the optional argument is equivalent to --delete-bad-limit=1500000.
--assume-completeness
There are various way (e.g. the next few options) to configure the prover to be strongly incomplete in the general case. E will detect when such an option is selected and return corresponding exit states (i.e. it will not claim satisfiability just because it ran out of unprocessed clauses). If you _know_ that for your class of problems the selected strategy is still complete, use this option to tell the system that this is the case.
--disable-eq-factoring
Disable equality factoring. This makes the prover incomplete for general non-Horn problems, but helps for some specialized classes. It is not necessary to disable equality factoring for Horn problems, as Horn clauses are not factored anyways.
--disable-paramod-into-neg-units
Disable paramodulation into negative unit clause. This makes the prover incomplete in the general case, but helps for some specialized classes.
--disable-given-clause-fw-contraction
Disable simplification and subsumption of the newly selected given clause (clauses are still simplified when they are generated). In general, this breaks some basic assumptions of the DISCOUNT loop proof search procedure. However, there are some problem classes in which this simplifications empirically never occurs. In such cases, we can save significant overhead. The option _should_ work in all cases, but is not expected to improve things in most cases.
--simul-paramod
Use simultaneous paramodulation to implement superposition. Default is to use plain paramodulation. This is an experimental feature.
--oriented-simul-paramod
Use simultaneous paramodulation for oriented from-literals. This is an experimental feature.
--split-clauses[=<arg>]
Determine which clauses should be subject to splitting. The argument is the binary 'OR' of values for the desired classes:
1:
Horn clauses
2:
Non-Horn clauses
4:
Negative clauses
8:
Positive clauses
16:
Clauses with both positive and negative literals
Each set bit adds that class to the set of clauses which will be split. The option without the optional argument is equivalent to --split-clauses=7.
--split-method=<arg>
Determine how to treat ground literals in splitting. The argument is either '0' to denote no splitting of ground literals (they are all assigned to the first split clause produced), '1' to denote that all ground literals should form a single new clause, or '2', in which case ground literals are treated as usual and are all split off into individual clauses.
--split-aggressive
Apply splitting to new clauses (after simplification) and before evaluation. By default, splitting (if activated) is only performed on selected clauses.
--split-reuse-defs
If possible, reuse previous definitions for splitting.
--reweight-limit[=<arg>]
Set the number of new unprocessed clauses after which the set of unprocessed clauses will be reevaluated. The option without the optional argument is equivalent to --reweight-limit=30000.
-t <arg>
--term-ordering=<arg>
Select an ordering type (currently Auto, LPO, LPO4, KBO or KBO1). -tAuto is suggested, in particular with -xAuto. KBO and KBO1 are different implementations of the same ordering, KBO is usually faster and has had more testing. Similarly, LPO4 is an new, equivalent but superior implementation of LPO.
-w <arg>
--order-weight-generation=<arg>
Select a method for the generation of weights for use with the term ordering. Run 'eprover -w none' for a list of options.
--order-weights=<arg>
Describe a (partial) assignments of weights to function symbols for term orderings (in particular, KBO). You can specify a list of weights of the form 'f1:w1,f2:w2, ...'. Since a total weight assignment is needed, E will _first_ apply any weight generation scheme specified (or the default one), and then modify the weights as specified. Note that E performs only very basic sanity checks, so you probably can specify weights that break KBO constraints.
-G <arg>
--order-precedence-generation=<arg>
Select a method for the generation of a precedence for use with the term ordering. Run 'eprover -G none' for a list of options.
-c <arg>
--order-constant-weight=<arg>
Set a special weight > 0 for constants in the term ordering. By default, constants are treated like other function symbols.
--precedence[=<arg>]
Describe a (partial) precedence for the term ordering used for the proof attempt. You can specify a comma-separated list of precedence chains, where a precedence chain is a list of function symbols (which all have to appear in the proof problem), connected by >, <, or =. If this option is used in connection with --order-precedence-generation, the partial ordering will be completed using the selected method, otherwise the prover runs with a non-ground-total ordering. The option without the optional argument is equivalent to --precedence=.
--lpo-recursion-limit[=<arg>]
Set a depth limit for LPO comparisons. Most comparisons do not need more than 10 or 20 levels of recursion. By default, recursion depth is limited to 1000 to avoid stack overflow problems. If the limit is reached, the prover assumes that the terms are uncomparable. Smaller values make the comparison attempts faster, but less exact. Larger values have the opposite effect. Values up to 20000 should be save on most operating systems. If you run into segmentation faults while using LPO or LPO4, first try to set this limit to a reasonable value. If the problem persists, send a bug report ;-) The option without the optional argument is equivalent to --lpo-recursion-limit=100.
--restrict-literal-comparisons
Make all literals uncomparable in the term ordering (i.e. do not use the term ordering to restrict paramodulation, equality resolution and factoring to certain literals. This is necessary to make Set-of-Support-strategies complete for the non-equational case (It still is incomplete for the equational case, but pretty useless anyways).
--sos-uses-input-types
If input is TPTP format, use TPTP conjectures for initializing the Set of Support. If not in TPTP format, use E-LOP queries (clauses of the form ?-l(X),...,m(Y)). Normally, all negative clauses are used. Please note that most E heuristics do not use this information at all, it is currently only useful for certain parameter settings (including the SimulateSOS priority function).
--destructive-er
Allow destructive equality resolution inferences on pure-variable literals of the form X!=Y, i.e. replace the original clause with the result of an equality resolution inference on this literal.
--strong-destructive-er
Allow destructive equality resolution inferences on literals of the form X!=t (where X does not occur in t), i.e. replace the original clause with the result of an equality resolution inference on this literal. Unless I am brain-dead, this maintains completeness, although the proof is rather tricky.
--destructive-er-aggressive
Apply destructive equality resolution to all newly generated clauses, not just to selected clauses. Implies --destructive-er.
--forward-context-sr
Apply contextual simplify-reflect with processed clauses to the given clause.
--forward-context-sr-aggressive
Apply contextual simplify-reflect with processed clauses to new clauses. Implies --forward-context-sr.
--backward-context-sr
Apply contextual simplify-reflect with the given clause to processed clauses.
-g
--prefer-general-demodulators
Prefer general demodulators. By default, E prefers specialized demodulators. This affects in which order the rewrite index is traversed.
-F <arg>
--forward_demod_level=<arg>
Set the desired level for rewriting of unprocessed clauses. A value of 0 means no rewriting, 1 indicates to use rules (orientable equations) only, 2 indicates full rewriting with rules and instances of unorientable equations. Default behavior is 2.
--strong-rw-inst
Instantiate unbound variables in matching potential demodulators with a small constant terms.
-u
--strong-forward-subsumption
Try multiple positions and unit-equations to try to equationally subsume a single new clause. Default is to search for a single position.
--watchlist[=<arg>]
Give the name for a file containing clauses to be watched for during the saturation process. If a clause is generated that subsumes a watchlist clause, the subsumed clause is removed from the watchlist. The prover will terminate when the watchlist is empty. If you want to use the watchlist for guiding the proof, put the empty clause onto the list and use the built-in clause selection heuristic 'UseWatchlist' (or build a heuristic yourself using the priority functions 'PreferWatchlist' and 'DeferWatchlist'). Use the argument 'Use inline watchlist type' (or no argument) and the special clause type 'watchlist' if you want to put watchlist clauses into the normal input stream. This is only supported for TPTP input formats. The option without the optional argument is equivalent to --watchlist='Use inline watchlist type'.
--no-watchlist-simplification
Normally, that watchlist is brought into normal form with respect to the current processed clause set and certain simplifications. This option disables this behaviour.
--conventional-subsumption
Equivalent to --subsumption-indexing=None.
--subsumption-indexing=<arg>
Determine choice of indexing for (most) subsumption operations. Choices are 'None' for naive subsumption, 'Direct' for direct mapped FV-Indexing, 'Perm' for permuted FV-Indexing and 'PermOpt' for permuted FV-Indexing with deletion of (suspected) non-informative features. Default behaviour is 'Perm'.
--fvindex-featuretypes=<arg>
Select the feature types used for indexing. Choices are "None" to disable FV-indexing, "AC" for AC compatible features (the default) (literal number and symbol counts), "SS" for set subsumption compatible features (symbol depth), and "All" for all features.Unless you want to measure the effects of the different features, I suggest you stick with the default.
--fvindex-maxfeatures[=<arg>]
Set the maximum initial number of symbols for feature computation. Depending on the feature selection, a value of X here will convert into 2X+2 features (for set subsumption features), 2X+4 features (for AC-compatible features) or 4X+6 features (if all features are used, the default). Note that the actually used set of features may be smaller than this if the signature does not contain enough symbols.For the Perm and PermOpt version, this is _also_ used to set the maximum depth of the feature vector index. Yes, I should probably make this into two separate options. If you select a small value here, you should probably not use "Direct" for the --subsumption-indexing option. The option without the optional argument is equivalent to --fvindex-maxfeatures=200.
--fvindex-slack[=<arg>]
Set the number of slots reserved in the index for function symbols that may be introduced into the signature later, e.g. by splitting. If no new symbols are introduced, this just wastes time and memory. If PermOpt is chosen, the slackness slots will be deleted from the index anyways, but will still waste (a little) time in computing feature vectors. The option without the optional argument is equivalent to --fvindex-slack=0.
--simplify-with-unprocessed-units[=<arg>]
Determine whether to use unprocessed unit clauses for simplify-reflect (unit-cutting) and unit subsumption. Possible values are 'NoSimplify' for strict DISCOUNT loop, 'TopSimplify' to use unprocessed units at the top level only, or 'FullSimplify' to use positive units even within equations. The option without the optional argument is equivalent to --simplify-with-unprocessed-units=TopSimplify.
-D <arg>
--define-weight-function=<arg>
Define a weight function (see manual for details). Later definitions override previous definitions.
-H <arg>
--define-heuristic=<arg>
Define a clause selection heuristic (see manual for details). Later definitions override previous definitions.
--free-numbers
Treat numbers (strings of decimal digits) as normal free function symbols in the input. By default, number now are supposed to denote domain constants and to be implicitly different from each other.
--free-objects
Treat object identifiers (strings in double quotes) as normal free function symbols in the input. By default, object identifiers now represent domain objects and are implicitly different from each other (and from numbers, unless those are declared to be free).
--definitional-cnf[=<arg>]
Use the new clausification algorithm that possibly introduces definitions for subformulas to avoid exponential blow-up. This is now the default. The optional argument is a fudge factor that determines when a definition is introduced. 0 disables definitions, the default works well. The option without the optional argument is equivalent to --definitional-cnf=24.

AUTHOR

Stephan Schulz <schulz@eprover.org> Copyright 1998-2006 by Stephan Schulz <schulz@eprover.org>

You can find the latest version of E and additional information at http://www.eprover.org

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program (it should be contained in the top level directory of the distribution in the file COPYING); if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

The original copyright holder can be contacted as

Stephan Schulz (I4)
Technische Universitaet Muenchen
Institut fuer Informatik
Boltzmannstrasse 3
85748 Garching bei Muenchen
Germany

SEE ALSO

eground(1), epclextract(1),
PDF manual /usr/share/doc/eprover/eprover.pdf.gz for a more detailed description.