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Theorem nffrfor 4333
Description: Bound-variable hypothesis builder for well-founded relations. (Contributed by Stefan O'Rear, 20-Jan-2015.) (Revised by Mario Carneiro, 14-Oct-2016.)
Hypotheses
Ref Expression
nffrfor.r 𝑥𝑅
nffrfor.a 𝑥𝐴
nffrfor.s 𝑥𝑆
Assertion
Ref Expression
nffrfor 𝑥 FrFor 𝑅𝐴𝑆

Proof of Theorem nffrfor
Dummy variables 𝑢 𝑣 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 df-frfor 4316 . 2 ( FrFor 𝑅𝐴𝑆 ↔ (∀𝑢𝐴 (∀𝑣𝐴 (𝑣𝑅𝑢𝑣𝑆) → 𝑢𝑆) → 𝐴𝑆))
2 nffrfor.a . . . 4 𝑥𝐴
3 nfcv 2312 . . . . . . . 8 𝑥𝑣
4 nffrfor.r . . . . . . . 8 𝑥𝑅
5 nfcv 2312 . . . . . . . 8 𝑥𝑢
63, 4, 5nfbr 4035 . . . . . . 7 𝑥 𝑣𝑅𝑢
7 nffrfor.s . . . . . . . 8 𝑥𝑆
87nfcri 2306 . . . . . . 7 𝑥 𝑣𝑆
96, 8nfim 1565 . . . . . 6 𝑥(𝑣𝑅𝑢𝑣𝑆)
102, 9nfralxy 2508 . . . . 5 𝑥𝑣𝐴 (𝑣𝑅𝑢𝑣𝑆)
117nfcri 2306 . . . . 5 𝑥 𝑢𝑆
1210, 11nfim 1565 . . . 4 𝑥(∀𝑣𝐴 (𝑣𝑅𝑢𝑣𝑆) → 𝑢𝑆)
132, 12nfralxy 2508 . . 3 𝑥𝑢𝐴 (∀𝑣𝐴 (𝑣𝑅𝑢𝑣𝑆) → 𝑢𝑆)
142, 7nfss 3140 . . 3 𝑥 𝐴𝑆
1513, 14nfim 1565 . 2 𝑥(∀𝑢𝐴 (∀𝑣𝐴 (𝑣𝑅𝑢𝑣𝑆) → 𝑢𝑆) → 𝐴𝑆)
161, 15nfxfr 1467 1 𝑥 FrFor 𝑅𝐴𝑆
Colors of variables: wff set class
Syntax hints:  wi 4  wnf 1453  wcel 2141  wnfc 2299  wral 2448  wss 3121   class class class wbr 3989   FrFor wfrfor 4312
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 704  ax-5 1440  ax-7 1441  ax-gen 1442  ax-ie1 1486  ax-ie2 1487  ax-8 1497  ax-10 1498  ax-11 1499  ax-i12 1500  ax-bndl 1502  ax-4 1503  ax-17 1519  ax-i9 1523  ax-ial 1527  ax-i5r 1528  ax-ext 2152
This theorem depends on definitions:  df-bi 116  df-3an 975  df-tru 1351  df-nf 1454  df-sb 1756  df-clab 2157  df-cleq 2163  df-clel 2166  df-nfc 2301  df-ral 2453  df-v 2732  df-un 3125  df-in 3127  df-ss 3134  df-sn 3589  df-pr 3590  df-op 3592  df-br 3990  df-frfor 4316
This theorem is referenced by:  nffr  4334
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