Generates a tactic from the assumptions, discards the assumptions and
applies the tactic.
DESCRIPTION
When applied to a function and a goal, POP_ASSUM_LIST applies
the function to a list of theorems corresponding to the ASSUMEd
assumptions of the goal, then applies the resulting tactic to the goal
with an empty assumption list.
POP_ASSUM_LIST f ({A1,...,An} ?- t) = f [A1 |- A1, ..., An |- An] (?- t)
FAILURE
Fails if the function fails when applied to the list of ASSUMEd assumptions,
or if the resulting tactic fails when applied to the goal with no
assumptions.
COMMENTS
There is nothing magical about POP_ASSUM_LIST: the same effect can be
achieved by using ASSUME a explicitly wherever the assumption a is
used. If POP_ASSUM_LIST is used, it is unwise to select elements by
number from the ASSUMEd-assumption list, since this introduces a dependency
on ordering.
EXAMPLE
Suppose we have a goal of the following form:
{a /\ b, c, (d /\ e) /\ f} ?- t
Then we can split the conjunctions in the assumption list apart by
applying the tactic:
POP_ASSUM_LIST (MAP_EVERY STRIP_ASSUME_TAC)
which results in the new goal:
{a, b, c, d, e, f} ?- t
USES
Making more delicate use of the assumption list than simply rewriting or
using resolution.