Definition df-nf 335

Description: Definition of not-free predicate.

Assertion

Ref	Expression
df-nf	⊦ (Ⅎx𝜑 ⧟ (~ 𝜑 ⊸ ∀x𝜑))

Detailed syntax breakdown of Definition df-nf

Step	Hyp	Ref	Expression
1		wph	. . 3 wff 𝜑
2		vx	. . 3 var x
3	1, 2	wnf 320	. 2 wff Ⅎx𝜑
4	1	wneg 3	. . 3 wff ~ 𝜑
5	1, 2	wal 318	. . 3 wff ∀x𝜑
6	4, 5	wli 61	. 2 wff (~ 𝜑 ⊸ ∀x𝜑)
7	3, 6	wlb 55	1 wff (Ⅎx𝜑 ⧟ (~ 𝜑 ⊸ ∀x𝜑))

This definition is referenced by: (None)