Theorem eqsid | index | src |

theorem eqsid (A: set): $ A == A $;
StepHypRefExpression
1 biid
x e. A <-> x e. A
2 1 ax_gen
A. x (x e. A <-> x e. A)
3 2 conv eqs
A == A

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp), axs_pred_calc (ax_gen)