Theorem ineq0 | index | src |

theorem ineq0 (A B: set): $ A i^i B == 0 <-> A C_ Compl B $;
StepHypRefExpression
1 bitr3
(A i^i Compl (Compl B) == 0 <-> A i^i B == 0) -> (A i^i Compl (Compl B) == 0 <-> A C_ Compl B) -> (A i^i B == 0 <-> A C_ Compl B)
2 eqseq1
A i^i Compl (Compl B) == A i^i B -> (A i^i Compl (Compl B) == 0 <-> A i^i B == 0)
3 ineq2
Compl (Compl B) == B -> A i^i Compl (Compl B) == A i^i B
4 cplcpl
Compl (Compl B) == B
5 3, 4 ax_mp
A i^i Compl (Compl B) == A i^i B
6 2, 5 ax_mp
A i^i Compl (Compl B) == 0 <-> A i^i B == 0
7 1, 6 ax_mp
(A i^i Compl (Compl B) == 0 <-> A C_ Compl B) -> (A i^i B == 0 <-> A C_ Compl B)
8 incpleq0
A i^i Compl (Compl B) == 0 <-> A C_ Compl B
9 7, 8 ax_mp
A i^i B == 0 <-> A C_ Compl 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), axs_peano (peano1, peano2, peano5, addeq, muleq, add0, addS, mul0, mulS)