This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: Transposition of a composition. (Contributed by Mario Carneiro, 4-Oct-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | tposco |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | coass | ||
| 2 | dftpos4 | ||
| 3 | dftpos4 | ||
| 4 | 3 | coeq2i | |
| 5 | 1 2 4 | 3eqtr4i |