Description: A singleton of an ordered pair is a function. Theorem 10.5 of Quine p. 65. (Contributed by NM, 12-Aug-1994)
Ref | Expression | ||
---|---|---|---|
Hypotheses | funsn.1 | |
|
funsn.2 | |
||
Assertion | funsn | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | funsn.1 | |
|
2 | funsn.2 | |
|
3 | funsng | |
|
4 | 1 2 3 | mp2an | |