![]() |
Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
Mirrors > Home > MPE Home > Th. List > unssd | Unicode version |
Description: A deduction showing the union of two subclasses is a subclass. (Contributed by Jonathan Ben-Naim, 3-Jun-2011.) |
Ref | Expression |
---|---|
unssd.1 | |
unssd.2 |
Ref | Expression |
---|---|
unssd |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | unssd.1 | . 2 | |
2 | unssd.2 | . 2 | |
3 | unss 3677 | . . 3 | |
4 | 3 | biimpi 194 | . 2 |
5 | 1, 2, 4 | syl2anc 661 | 1 |
Copyright terms: Public domain | W3C validator |