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Mirrors > Home > MPE Home > Th. List > dfss3 | Structured version Visualization version Unicode version |
Description: Alternate definition of subclass relationship. (Contributed by NM, 14-Oct-1999.) |
Ref | Expression |
---|---|
dfss3 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dfss2 3591 | . 2 | |
2 | df-ral 2917 | . 2 | |
3 | 1, 2 | bitr4i 267 | 1 |
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