Attempt to prove a term by first-order proof search using leanCop
connection-based prover.
DESCRIPTION
A call LEANCOP[theorems] `tm` will attempt to prove tm using pure
first-order reasoning, taking theorems as the starting-point. It will usually
either prove it completely or run for an infeasibly long time, but it may
sometimes fail quickly.
Although LEANCOP is capable of some fairly non-obvious pieces of first-order
reasoning, and will handle equality adequately, it does purely logical
reasoning. It will exploit no special properties of the constants in the goal,
other than equality and logical primitives. Any properties that are needed must
be supplied explicitly in the theorem list, e.g. LE_REFL to tell it that <=
on natural numbers is reflexive, or REAL_ADD_SYM to tell it that addition on
real numbers is symmetric.
FAILURE CONDITIONS
Fails if the term is unprovable within the search bounds.
EXAMPLE
A typical application is to prove some elementary logical lemma for use inside
a tactic proof:
# LEANCOP [EXTENSION; IN_INSERT]
`x INSERT y INSERT s = y INSERT x INSERT s`;;
USES
Generating simple logical lemmas as part of a large proof.