CONJ_DISCH
Drule.CONJ_DISCH : (term -> thm -> thm)
Discharges an assumption and conjoins it to both sides of an equation.
Given an term t
and a theorem A |- t1 = t2
,
which is an equation between boolean terms, CONJ_DISCH
returns A - {t} |- (t /\ t1) = (t /\ t2)
, i.e. conjoins
t
to both sides of the equation, removing t
from the assumptions if it was there.
A |- t1 = t2
------------------------------ CONJ_DISCH "t"
A - {t} |- t /\ t1 = t /\ t2
Fails unless the theorem is an equation, both sides of which, and the
term provided are of type bool
.