Theorem dmreslam | index | src |

theorem dmreslam {x: nat} (A: set x) (a: nat x): $ Dom ((\ x, a) |` A) == A $;
StepHypRefExpression
1 eqstr
Dom ((\ x, a) |` A) == Dom (\ x, a) i^i A -> Dom (\ x, a) i^i A == A -> Dom ((\ x, a) |` A) == A
2 dmres
Dom ((\ x, a) |` A) == Dom (\ x, a) i^i A
3 1, 2 ax_mp
Dom (\ x, a) i^i A == A -> Dom ((\ x, a) |` A) == A
4 eqstr
Dom (\ x, a) i^i A == _V i^i A -> _V i^i A == A -> Dom (\ x, a) i^i A == A
5 ineq1
Dom (\ x, a) == _V -> Dom (\ x, a) i^i A == _V i^i A
6 dmlam
Dom (\ x, a) == _V
7 5, 6 ax_mp
Dom (\ x, a) i^i A == _V i^i A
8 4, 7 ax_mp
_V i^i A == A -> Dom (\ x, a) i^i A == A
9 inv1
_V i^i A == A
10 8, 9 ax_mp
Dom (\ x, a) i^i A == A
11 3, 10 ax_mp
Dom ((\ x, a) |` A) == 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), axs_the (theid, the0), axs_peano (peano1, peano2, peano5, addeq, muleq, add0, addS, mul0, mulS)