Theorem ax6er

Description: Commuted form of ax6e . (Could be placed right after ax6e ). (Contributed by BJ, 15-Sep-2018)

	Ref	Expression
Assertion	ax6er	$$⊢\exists xy=x$$

Proof

Step	Hyp	Ref	Expression
1		ax6e	$$⊢\exists xx=y$$
2		equcomi	$$⊢x=y\to y=x$$
3	1 2	eximii	$$⊢\exists xy=x$$