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| Mirrors > Home > NFE Home > Th. List > df-br | Unicode version | ||
| Description: Define a general binary
relation.  Note that the syntax is simply three
     class symbols in a row.  Definition 6.18 of [TakeutiZaring] p. 29
     generalized to arbitrary classes.  Class  | 
| Ref | Expression | 
|---|---|
| df-br | 
 | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | cA | 
. . 3
 | |
| 2 | cB | 
. . 3
 | |
| 3 | cR | 
. . 3
 | |
| 4 | 1, 2, 3 | wbr 4640 | 
. 2
 | 
| 5 | 1, 2 | cop 4562 | 
. . 3
 | 
| 6 | 5, 3 | wcel 1710 | 
. 2
 | 
| 7 | 4, 6 | wb 176 | 
1
 | 
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