Theorem bj-a1k 31705

Description: Weakening of ax-1 6. This shortens the proofs of dfwe2 6873, ordunisuc2 6936, r111 8521, smo11 7348. (Contributed by BJ, 11-Aug-2020.)

Assertion

Ref	Expression
bj-a1k	⊢ (𝜑 → (𝜓 → (𝜒 → 𝜓)))

Proof of Theorem bj-a1k

Step	Hyp	Ref	Expression
1		ax-1 6	. 2 ⊢ (𝜓 → (𝜒 → 𝜓))
2	1	a1i 11	1 ⊢ (𝜑 → (𝜓 → (𝜒 → 𝜓)))

Syntax hints:   → wi 4

This theorem was proved from axioms:  ax-mp 5  ax-1 6

This theorem is referenced by: (None)