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Mirrors > Home > ILE Home > Th. List > nfif | GIF version |
Description: Bound-variable hypothesis builder for a conditional operator. (Contributed by NM, 16-Feb-2005.) (Proof shortened by Andrew Salmon, 26-Jun-2011.) |
Ref | Expression |
---|---|
nfif.1 | ⊢ Ⅎ𝑥𝜑 |
nfif.2 | ⊢ Ⅎ𝑥𝐴 |
nfif.3 | ⊢ Ⅎ𝑥𝐵 |
Ref | Expression |
---|---|
nfif | ⊢ Ⅎ𝑥if(𝜑, 𝐴, 𝐵) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nfif.1 | . . . 4 ⊢ Ⅎ𝑥𝜑 | |
2 | 1 | a1i 9 | . . 3 ⊢ (⊤ → Ⅎ𝑥𝜑) |
3 | nfif.2 | . . . 4 ⊢ Ⅎ𝑥𝐴 | |
4 | 3 | a1i 9 | . . 3 ⊢ (⊤ → Ⅎ𝑥𝐴) |
5 | nfif.3 | . . . 4 ⊢ Ⅎ𝑥𝐵 | |
6 | 5 | a1i 9 | . . 3 ⊢ (⊤ → Ⅎ𝑥𝐵) |
7 | 2, 4, 6 | nfifd 3418 | . 2 ⊢ (⊤ → Ⅎ𝑥if(𝜑, 𝐴, 𝐵)) |
8 | 7 | mptru 1298 | 1 ⊢ Ⅎ𝑥if(𝜑, 𝐴, 𝐵) |
Colors of variables: wff set class |
Syntax hints: ⊤wtru 1290 Ⅎwnf 1394 Ⅎwnfc 2215 ifcif 3393 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 104 ax-ia2 105 ax-ia3 106 ax-in1 579 ax-in2 580 ax-io 665 ax-5 1381 ax-7 1382 ax-gen 1383 ax-ie1 1427 ax-ie2 1428 ax-8 1440 ax-10 1441 ax-11 1442 ax-i12 1443 ax-bndl 1444 ax-4 1445 ax-17 1464 ax-i9 1468 ax-ial 1472 ax-i5r 1473 ax-ext 2070 |
This theorem depends on definitions: df-bi 115 df-tru 1292 df-fal 1295 df-nf 1395 df-sb 1693 df-clab 2075 df-cleq 2081 df-clel 2084 df-nfc 2217 df-if 3394 |
This theorem is referenced by: nfsum1 10745 nfsum 10746 isumrblem 10765 isummolem2a 10771 zisum 10774 fisum 10778 isumss 10783 isumss2 10785 fisumcvg2 10786 fsum3cvg2 10787 |
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