Theorem bj-exalimi

Description: An inference for distributing quantifiers over a nested implication. The canonical derivation from its closed form bj-exalim (using mpg ) has fewer essential steps, but more steps in total (yielding a longer compressed proof). (Almost) the general statement that speimfw proves. (Contributed by BJ, 29-Sep-2019)

	Ref	Expression
Hypothesis	bj-exalimi.1	|- ( ph -> ( ps -> ch ) )
Assertion	bj-exalimi	|- ( E. x ph -> ( A. x ps -> E. x ch ) )

Proof

Step	Hyp	Ref	Expression
1		bj-exalimi.1	|- ( ph -> ( ps -> ch ) )
2	1	com12	|- ( ps -> ( ph -> ch ) )
3	2	aleximi	|- ( A. x ps -> ( E. x ph -> E. x ch ) )
4	3	com12	|- ( E. x ph -> ( A. x ps -> E. x ch ) )