Theorem inss2 | index | src |

theorem inss2 (A B: set): $ A i^i B C_ B $;
StepHypRefExpression
1 sseq1
B i^i A == A i^i B -> (B i^i A C_ B <-> A i^i B C_ B)
2 incom
B i^i A == A i^i B
3 1, 2 ax_mp
B i^i A C_ B <-> A i^i B C_ B
4 inss1
B i^i A C_ B
5 3, 4 mpbi
A i^i B C_ 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)