Theorem wsuceq123 35795

Description: Equality theorem for well-founded successor. (Contributed by Scott Fenton, 13-Jun-2018.) (Proof shortened by AV, 10-Oct-2021.)

Assertion

Ref	Expression
wsuceq123	⊢ ((𝑅 = 𝑆 ∧ 𝐴 = 𝐵 ∧ 𝑋 = 𝑌) → wsuc(𝑅, 𝐴, 𝑋) = wsuc(𝑆, 𝐵, 𝑌))

Proof of Theorem wsuceq123

Step	Hyp	Ref	Expression
1		simp1 1135	. . . . 5 ⊢ ((𝑅 = 𝑆 ∧ 𝐴 = 𝐵 ∧ 𝑋 = 𝑌) → 𝑅 = 𝑆)
2	1	cnveqd 5888	. . . 4 ⊢ ((𝑅 = 𝑆 ∧ 𝐴 = 𝐵 ∧ 𝑋 = 𝑌) → ◡𝑅 = ◡𝑆)
3		predeq123 6323	. . . 4 ⊢ ((◡𝑅 = ◡𝑆 ∧ 𝐴 = 𝐵 ∧ 𝑋 = 𝑌) → Pred(◡𝑅, 𝐴, 𝑋) = Pred(◡𝑆, 𝐵, 𝑌))
4	2, 3	syld3an1 1409	. . 3 ⊢ ((𝑅 = 𝑆 ∧ 𝐴 = 𝐵 ∧ 𝑋 = 𝑌) → Pred(◡𝑅, 𝐴, 𝑋) = Pred(◡𝑆, 𝐵, 𝑌))
5		simp2 1136	. . 3 ⊢ ((𝑅 = 𝑆 ∧ 𝐴 = 𝐵 ∧ 𝑋 = 𝑌) → 𝐴 = 𝐵)
6	4, 5, 1	infeq123d 9518	. 2 ⊢ ((𝑅 = 𝑆 ∧ 𝐴 = 𝐵 ∧ 𝑋 = 𝑌) → inf(Pred(◡𝑅, 𝐴, 𝑋), 𝐴, 𝑅) = inf(Pred(◡𝑆, 𝐵, 𝑌), 𝐵, 𝑆))
7		df-wsuc 35793	. 2 ⊢ wsuc(𝑅, 𝐴, 𝑋) = inf(Pred(◡𝑅, 𝐴, 𝑋), 𝐴, 𝑅)
8		df-wsuc 35793	. 2 ⊢ wsuc(𝑆, 𝐵, 𝑌) = inf(Pred(◡𝑆, 𝐵, 𝑌), 𝐵, 𝑆)
9	6, 7, 8	3eqtr4g 2799	1 ⊢ ((𝑅 = 𝑆 ∧ 𝐴 = 𝐵 ∧ 𝑋 = 𝑌) → wsuc(𝑅, 𝐴, 𝑋) = wsuc(𝑆, 𝐵, 𝑌))

Syntax hints:   → wi 4   ∧ w3a 1086   = wceq 1536  ^◡ccnv 5687  Predcpred 6321  infcinf 9478  wsuccwsuc 35791

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1791  ax-4 1805  ax-5 1907  ax-6 1964  ax-7 2004  ax-8 2107  ax-9 2115  ax-ext 2705

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3an 1088  df-tru 1539  df-fal 1549  df-ex 1776  df-sb 2062  df-clab 2712  df-cleq 2726  df-clel 2813  df-ral 3059  df-rex 3068  df-rab 3433  df-v 3479  df-dif 3965  df-un 3967  df-in 3969  df-ss 3979  df-nul 4339  df-if 4531  df-sn 4631  df-pr 4633  df-op 4637  df-uni 4912  df-br 5148  df-opab 5210  df-xp 5694  df-cnv 5696  df-dm 5698  df-rn 5699  df-res 5700  df-ima 5701  df-pred 6322  df-sup 9479  df-inf 9480  df-wsuc 35793

This theorem is referenced by:  wsuceq1  35796  wsuceq2  35797  wsuceq3  35798