Axiom ax-eqtypi 77

Description: Deduce equality of types from equality of expressions. (This is unnecessary but eliminates a lot of hypotheses.) (New usage is discouraged.) (Contributed by Mario Carneiro, 7-Oct-2014.)

Hypotheses

Ref	Expression
eqcomi.1	⊢ A:α
eqcomi.2	⊢ R⊧[A = B]

Assertion

Ref	Expression
ax-eqtypi	⊢ B:α

Detailed syntax breakdown of Axiom ax-eqtypi

Step	Hyp	Ref	Expression
1		hal	. 2 type α
2		tb	. 2 term B
3	1, 2	wffMMJ2t 12	1 wff B:α

This axiom is referenced by:  eqtypi  78