Description: Axiom of Replacement using abbreviations. Axiom 39(vi) of Quine p. 284. Compare Exercise 9 of TakeutiZaring p. 29. (Contributed by NM, 10-Sep-2006) Shorten proof and avoid ax-10 , ax-12 . (Revised by SN, 19-Dec-2024)
Ref | Expression | ||
---|---|---|---|
Assertion | funimaexg | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dffun6 | |
|
2 | 1 | simprbi | |
3 | dfima2 | |
|
4 | axrep6g | |
|
5 | 3 4 | eqeltrid | |
6 | 2 5 | sylan2 | |
7 | 6 | ancoms | |