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| Description: Define a one-to-one function. For equivalent definitions see dff12 4735 and dff13 4984. Compare Definition 6.15(5) of [TakeutiZaring] p. 27. We use their notation ("1-1" above the arrow). |
| Ref | Expression |
|---|---|
| df-f1 |
|
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | cA |
. . 3
| |
| 2 | cB |
. . 3
| |
| 3 | cF |
. . 3
| |
| 4 | 1, 2, 3 | wf1 4160 |
. 2
|
| 5 | 1, 2, 3 | wf 4159 |
. . 3
|
| 6 | 3 | ccnv 4150 |
. . . 4
|
| 7 | 6 | wfun 4157 |
. . 3
|
| 8 | 5, 7 | wa 433 |
. 2
|
| 9 | 4, 8 | wb 231 |
1
|
| Colors of variables: wff set class |
| This definition is referenced by: f1eq1 4731 f1eq2 4732 f1eq3 4733 hbf1 4734 dff12 4735 f1f 4736 f1ss 4737 f1cnvcnv 4738 f1co 4739 dff1o2 4766 f1f1orn 4772 f1ores 4776 f1imacnv 4778 f11o 4791 f10 4792 tz7.48lem 5368 abianfp 5378 ssdomg 5671 sbthlem9 5727 fodomr 5759 1sdom 5859 inf3lem7OLD 6002 fodomnumlem 6273 fodom 6448 reeff1o 9207 infxpidmlem7OLD 9357 injrec2 15439 hmeogrp 15910 hartoglem 16468 |