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Mirrors > Home > NFE Home > Th. List > biorfi | Unicode version |
Description: A wff is equivalent to its disjunction with falsehood. (Contributed by NM, 23-Mar-1995.) |
Ref | Expression |
---|---|
biorfi.1 |
Ref | Expression |
---|---|
biorfi |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | biorfi.1 | . 2 | |
2 | orc 374 | . . 3 | |
3 | orel2 372 | . . 3 | |
4 | 2, 3 | impbid2 195 | . 2 |
5 | 1, 4 | ax-mp 8 | 1 |
Colors of variables: wff setvar class |
Syntax hints: wn 3 wb 176 wo 357 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-3 7 ax-mp 8 |
This theorem depends on definitions: df-bi 177 df-or 359 |
This theorem is referenced by: pm4.43 893 dn1 932 indifdir 3511 un0 3575 eqtfinrelk 4486 proj1op 4600 proj2op 4601 imadif 5171 |
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