Theorem nfsbn1 | index | src |

theorem nfsbn1 {x: nat} (a: nat) (b: nat x): $ FN/ x N[a / x] b $;
StepHypRefExpression
1 nfnv
FN/ x a
2 1 nfsbn1h
FN/ x N[a / x] b

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), axs_the (theid, the0)