Intuitionistic Logic Explorer |
< Previous
Next >
Nearby theorems |
||
Mirrors > Home > ILE Home > Th. List > pm4.72 | Unicode version |
Description: Implication in terms of biconditional and disjunction. Theorem *4.72 of [WhiteheadRussell] p. 121. (Contributed by NM, 30-Aug-1993.) (Proof shortened by Wolf Lammen, 30-Jan-2013.) |
Ref | Expression |
---|---|
pm4.72 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | olc 664 | . . 3 | |
2 | pm2.621 698 | . . 3 | |
3 | 1, 2 | impbid2 141 | . 2 |
4 | orc 665 | . . 3 | |
5 | bi2 128 | . . 3 | |
6 | 4, 5 | syl5 32 | . 2 |
7 | 3, 6 | impbii 124 | 1 |
Colors of variables: wff set class |
Syntax hints: wi 4 wb 103 wo 661 |
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-io 662 |
This theorem depends on definitions: df-bi 115 |
This theorem is referenced by: bigolden 896 ssequn1 3142 |
Copyright terms: Public domain | W3C validator |