Theorem finlamh | index | src |

theorem finlamh {x: nat} (A: set x) (v: nat x):
  $ finite A -> finite ((\ x, v) |` A) $;
StepHypRefExpression
1 fineq
(\ x, v) |` A == (\ a1, N[a1 / x] v) |` A -> (finite ((\ x, v) |` A) <-> finite ((\ a1, N[a1 / x] v) |` A))
2 reseq1
\ x, v == \ a1, N[a1 / x] v -> (\ x, v) |` A == (\ a1, N[a1 / x] v) |` A
3 cbvlams
\ x, v == \ a1, N[a1 / x] v
4 2, 3 ax_mp
(\ x, v) |` A == (\ a1, N[a1 / x] v) |` A
5 1, 4 ax_mp
finite ((\ x, v) |` A) <-> finite ((\ a1, N[a1 / x] v) |` A)
6 finlam
finite A -> finite ((\ a1, N[a1 / x] v) |` A)
7 5, 6 sylibr
finite A -> finite ((\ x, v) |` 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)