Description: Alternate proof of tfr2 using well-ordered recursion. (Contributed by Scott Fenton, 3-Aug-2020) (New usage is discouraged.) (Proof modification is discouraged.)
Ref | Expression | ||
---|---|---|---|
Hypothesis | tfrALT.1 | |
|
Assertion | tfr2ALT | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | tfrALT.1 | |
|
2 | epweon | |
|
3 | epse | |
|
4 | df-recs | |
|
5 | 1 4 | eqtri | |
6 | 5 | wfr2 | |
7 | 2 3 6 | mpanl12 | |
8 | predon | |
|
9 | 8 | reseq2d | |
10 | 9 | fveq2d | |
11 | 7 10 | eqtrd | |