Applies a tactic generated from the goal’s assumption list.
LIBRARY
bool
DESCRIPTION
When applied to a function of type thm list -> tactic and a goal,
ASSUM_LIST constructs a tactic by applying f to a list of ASSUMEd
assumptions of the goal, then applies that tactic to the goal.
ASSUM_LIST f ({A1,...,An} ?- t)
= f [A1 |- A1, ... , An |- An] ({A1,...,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.
COMMENTS
There is nothing magical about ASSUM_LIST: the same effect can usually be
achieved just as conveniently by using ASSUME a wherever the
assumption a is needed. If ASSUM_LIST is used, it is extremely unwise to
use a function which selects elements from its argument list by number, since
the ordering of assumptions should not be relied on.
EXAMPLE
The tactic:
ASSUM_LIST SUBST_TAC
makes a single parallel substitution using all the assumptions,
which can be useful if the rewriting tactics are too blunt for the required
task.
USES
Making more careful use of the assumption list than simply rewriting or
using resolution.