Axiom ax-subid 227

Assertion

Ref	Expression
ax-subid	⊦ ([x ≔ x] 𝜑 ⧟ 𝜑)

Detailed syntax breakdown of Axiom ax-subid

Step	Hyp	Ref	Expression
1		wph	. . 3 wff 𝜑
2		vx	. . 3 var x
3	2	nvar 203	. . 3 nilad x
4	1, 2, 3	wsub 207	. 2 wff [x ≔ x] 𝜑
5	4, 1	wlb 55	1 wff ([x ≔ x] 𝜑 ⧟ 𝜑)

This axiom is referenced by: (None)