formal/hol/Help/ASSUM_LIST.doc

\DOC ASSUM_LIST

\TYPE {ASSUM_LIST : (thm list -> tactic) -> tactic}

\SYNOPSIS
Applies a tactic generated from the goal's assumption list.

\KEYWORDS
theorem-tactic, assumption.

\DESCRIBE
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 {ASSUME}d
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 {ASSUME}d 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(MP_TAC o end_itlist CONJ)
}
\noindent adds a conjunction of all assumptions as an antecedent of a goal.

\USES
Making more careful use of the assumption list than simply rewriting.

\SEEALSO
ASM_REWRITE_TAC, EVERY_ASSUM, POP_ASSUM, POP_ASSUM_LIST, REWRITE_TAC.

\ENDDOC