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Mirrors > Home > ILE Home > Th. List > pm5.55dc | Unicode version |
Description: A disjunction is equivalent to one of its disjuncts, given a decidable disjunct. Based on theorem *5.55 of [WhiteheadRussell] p. 125. (Contributed by Jim Kingdon, 30-Mar-2018.) |
Ref | Expression |
---|---|
pm5.55dc | DECID |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-dc 776 | . 2 DECID | |
2 | biort 771 | . . . 4 | |
3 | 2 | bicomd 139 | . . 3 |
4 | biorf 695 | . . . 4 | |
5 | 4 | bicomd 139 | . . 3 |
6 | 3, 5 | orim12i 708 | . 2 |
7 | 1, 6 | sylbi 119 | 1 DECID |
Colors of variables: wff set class |
Syntax hints: wn 3 wi 4 wb 103 wo 661 DECID wdc 775 |
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-in2 577 ax-io 662 |
This theorem depends on definitions: df-bi 115 df-dc 776 |
This theorem is referenced by: (None) |
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