Intuitionistic Logic Explorer |
< Previous
Next >
Nearby theorems |
||
Mirrors > Home > ILE Home > Th. List > nfnf | Unicode version |
Description: If is not free in , it is not free in . (Contributed by Mario Carneiro, 11-Aug-2016.) (Proof shortened by Wolf Lammen, 30-Dec-2017.) |
Ref | Expression |
---|---|
nfal.1 |
Ref | Expression |
---|---|
nfnf |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-nf 1350 | . 2 | |
2 | nfal.1 | . . . 4 | |
3 | 2 | nfal 1468 | . . . 4 |
4 | 2, 3 | nfim 1464 | . . 3 |
5 | 4 | nfal 1468 | . 2 |
6 | 1, 5 | nfxfr 1363 | 1 |
Colors of variables: wff set class |
Syntax hints: wi 4 wal 1241 wnf 1349 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 99 ax-ia2 100 ax-ia3 101 ax-5 1336 ax-7 1337 ax-gen 1338 ax-4 1400 ax-ial 1427 ax-i5r 1428 |
This theorem depends on definitions: df-bi 110 df-nf 1350 |
This theorem is referenced by: nfnfc 2184 |
Copyright terms: Public domain | W3C validator |