![]() |
Intuitionistic Logic Explorer |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > ILE Home > Th. List > nfrexxy | GIF version |
Description: Not-free for restricted existential quantification where 𝑥 and 𝑦 are distinct. See nfrexya 2428 for a version with 𝑦 and 𝐴 distinct instead. (Contributed by Jim Kingdon, 30-May-2018.) |
Ref | Expression |
---|---|
nfralxy.1 | ⊢ Ⅎ𝑥𝐴 |
nfralxy.2 | ⊢ Ⅎ𝑥𝜑 |
Ref | Expression |
---|---|
nfrexxy | ⊢ Ⅎ𝑥∃𝑦 ∈ 𝐴 𝜑 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nftru 1407 | . . 3 ⊢ Ⅎ𝑦⊤ | |
2 | nfralxy.1 | . . . 4 ⊢ Ⅎ𝑥𝐴 | |
3 | 2 | a1i 9 | . . 3 ⊢ (⊤ → Ⅎ𝑥𝐴) |
4 | nfralxy.2 | . . . 4 ⊢ Ⅎ𝑥𝜑 | |
5 | 4 | a1i 9 | . . 3 ⊢ (⊤ → Ⅎ𝑥𝜑) |
6 | 1, 3, 5 | nfrexdxy 2422 | . 2 ⊢ (⊤ → Ⅎ𝑥∃𝑦 ∈ 𝐴 𝜑) |
7 | 6 | mptru 1305 | 1 ⊢ Ⅎ𝑥∃𝑦 ∈ 𝐴 𝜑 |
Colors of variables: wff set class |
Syntax hints: ⊤wtru 1297 Ⅎwnf 1401 Ⅎwnfc 2222 ∃wrex 2371 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-5 1388 ax-7 1389 ax-gen 1390 ax-ie1 1434 ax-ie2 1435 ax-4 1452 ax-17 1471 ax-ial 1479 ax-i5r 1480 ax-ext 2077 |
This theorem depends on definitions: df-bi 116 df-tru 1299 df-nf 1402 df-cleq 2088 df-clel 2091 df-nfc 2224 df-rex 2376 |
This theorem is referenced by: r19.12 2491 sbcrext 2930 nfuni 3681 nfiunxy 3778 rexxpf 4614 abrexex2g 5929 abrexex2 5933 nfrecs 6110 fimaxre2 10773 nfsum 10900 bezoutlemmain 11414 bj-findis 12582 strcollnfALT 12589 |
Copyright terms: Public domain | W3C validator |