This directory contains test problems for Otter 2.2.  The PC version
also contains the files OTTER.EXE and OTTER_32.EXE, and the Macintosh
version also contains the application Otter.

The files *.in are the input files, and *.stt are the ends of
corresponding output files from my computer, a SPARC 1+ (16 Mbytes).

UNIX.  The script run_all will run all of the problems and compare
statistics from your output files to *.stt.

PC, basic version.  Some of the test problems require a lot of memory
and/or a big stack and therefore do not complete on my computer, an
IBM PC/AT.  The file run_all.bat will run the test problems that run
successfully on my computer.  The problems that do not complete on my
computer are andrews, bool_ass, mv, w_sk, and dem_alu (the first 4 run
out of memory, and dem_alu crashes the PC because of a stack
overflow).

PC, 32-bit version.  The file run_32.bat will run all of the test
problems.  They all complete correctly on the computer I used.

Macintosh.  Some of the test problems require a lot of memory and/or a
big stack and therefore might not complete on your Macintosh.  All of
the test problems except dem_alu run correctly on the Macintosh IIx
(8Mbytes) that I used.  (dem_alu requires a large run-time stack,
and I assume that's the reason it fails.)

The test problems illustrate many of Otter's features.

A brief description of each problem:

andrews.in   -- Challenge problem from Peter Andrews.
bool_ass.in  -- Associativity of Boolean algebras, hyperresolution,
                P-formulation, lemmas.
cn.in        -- Sentential calculus.
dem_alu.in   -- Canonicalizing exclusive-or/and expressions.
ec.in        -- Equivalential calculus.
eval.in      -- Demodulation as a functional programming system.
grp_div.in   -- Axiomatization of group theory using right division.
kb_bench.in  -- Complete set of reductions for associative system with
		8 left identities and 8 right inverses.
kb_comm.in   -- Group theory commutator problem.
kb_group.in  -- Finding a complete set of reductions for free groups.
kb_x2_r.in   -- Commutativity of Boolean rings.
lifsch.in    -- A challenge from Vladimir Lifschitz.
mission.in   -- Missionaries and cannibals state-space search.
mv.in        -- Many-valued calculus.
pigeon.in    -- Propositional pigeon-hole problem (4 pigeons, 3 holes).
robbins      -- Robbins algebra.
salt.in      -- Propositional version of the salt and mustard problem.
sam_hyp.in   -- SAM's lemma with hyperresolution in P-formulation.
stage1.in    -- Stage 1 of the Kernel Strategy.
stage2.in    -- Stage 2 of the Kernel Strategy.
steam.in     -- Schubert's Steamroller.
str_bws.in   -- Combinatory logic: find a fixed point combinator from {B,W,S}.
subgroup.in  -- Subgroups of index 2 are normal (funny representation).
tba_gg.in    -- Ternary Boolean algebras, g(g(x)) = x.
w_sk.in      -- Combinatory logic: find a definition of W from {S,K}.
wang1.in     -- The exq1 problem from Wang.
x2_quant.in  -- Group theory, xx=e with paramodulation.
z11.in       -- Cyclic groups.

Cross-Indexes
-------------

Puzzles: mission, steam.

Algebra problems: bool_ass, kb_bench, kb_comm, kb_group, grp_div, kb_x2_r,
                  sam_hyp, subgroup, tba_gg, x2_quant, z11.

Logic problems: ec, cn, mv, stage1, stage2, str_bws, w_sk.

Demodulation problems: dem_alu, eval.

Propositional problems: pigeon, salt.

Miscellaneous first-order problems: andrews, lifsch, wang1.

-------------

Problems illustrating formula input: andrews, lifsch, steam, w_sk, x2_quant.

Problems illustrating evaluable functions/predicates: eval, mission.

Problems illustrating lexical ordering: dem_alu, eval.

Problems illustrating weighting: grp_div, stage1, wang1.

Problems illustrating answer literals: stage1, stage2, steam, str_bws,
         w_sk, cn, mv.

Problems illustrating binary resolution: andrews, lifsch, pigeon, salt, wang1.

Problems illustrating factoring: andrews, lifsch, wang1.

Problems illustrating hyperresolution/UR-resolution: bool_ass, cn, ec,
         mission, mv, sam_hyp, subgroup, steam, str_bws.

Problems illustrating paramodulation: grp_div, kb_bench, kb_comm, kb_group,
         kb_x2_r, robbins, stage1, stage2, tba_gg, w_sk, x2_quant, z11.

Problems illustrating of Knuth-Bendix completion: kb_comm, kb_group,
         kb_x2_r, kb_bench.

