theorem nfsbs1 {x: nat} (a: nat) (A: set x): $ FS/ x S[a / x] A $;
| Step | Hyp | Ref | Expression |
|---|
| 1 |
|
nfnv |
FN/ x a |
| 2 |
1 |
nfsbs1h |
FS/ x S[a / x] A |
Axiom use
axs_prop_calc
(ax_1,
ax_2,
ax_3,
ax_mp,
itru),
axs_pred_calc
(ax_gen,
ax_4,
ax_5,
ax_6,
ax_7,
ax_10,
ax_11,
ax_12),
axs_set
(elab,
ax_8)