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| Mirrors > Home > NFE Home > Th. List > dff1o3 | Unicode version | ||
| Description: Alternate definition of one-to-one onto function. (The proof was shortened by Andrew Salmon, 22-Oct-2011.) (Contributed by set.mm contributors, 25-Mar-1998.) (Revised by set.mm contributors, 22-Oct-2011.) | 
| Ref | Expression | 
|---|---|
| dff1o3 | 
 | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | df-3an 936 | 
. . 3
 | |
| 2 | an32 773 | 
. . 3
 | |
| 3 | 1, 2 | bitri 240 | 
. 2
 | 
| 4 | dff1o2 5292 | 
. 2
 | |
| 5 | df-fo 4794 | 
. . 3
 | |
| 6 | 5 | anbi1i 676 | 
. 2
 | 
| 7 | 3, 4, 6 | 3bitr4i 268 | 
1
 | 
| Colors of variables: wff setvar class | 
| Syntax hints:     | 
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1546 ax-5 1557 ax-17 1616 ax-9 1654 ax-8 1675 ax-6 1729 ax-7 1734 ax-11 1746 ax-12 1925 ax-ext 2334 | 
| This theorem depends on definitions: df-bi 177 df-or 359 df-an 360 df-3an 936 df-nan 1288 df-tru 1319 df-ex 1542 df-nf 1545 df-sb 1649 df-clab 2340 df-cleq 2346 df-clel 2349 df-nfc 2479 df-v 2862 df-nin 3212 df-compl 3213 df-in 3214 df-ss 3260 df-f 4792 df-f1 4793 df-fo 4794 df-f1o 4795 | 
| This theorem is referenced by: f1ofo 5294 f1ores 5301 resdif 5307 f11o 5316 | 
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