Theorem appslam | index | src |

theorem appslam (B: set) (a b: nat) {x: nat} (A: set x):
  $ x = a -> A == B $ >
  $ (\\ x, A) @ (a, b) = B @ b $;
StepHypRefExpression
1 eqtr
(\\ x, A) @ (a, b) = (S[a / x] A) @ b -> (S[a / x] A) @ b = B @ b -> (\\ x, A) @ (a, b) = B @ b
2 appslams
(\\ x, A) @ (a, b) = (S[a / x] A) @ b
3 1, 2 ax_mp
(S[a / x] A) @ b = B @ b -> (\\ x, A) @ (a, b) = B @ b
4 appeq1
S[a / x] A == B -> (S[a / x] A) @ b = B @ b
5 hyp h
x = a -> A == B
6 5 sbse
S[a / x] A == B
7 4, 6 ax_mp
(S[a / x] A) @ b = B @ b
8 3, 7 ax_mp
(\\ x, A) @ (a, b) = B @ 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)