Description: A permutation (element of the symmetric group) is a function from a set into itself. (Contributed by AV, 1-Jan-2019)
Ref | Expression | ||
---|---|---|---|
Hypotheses | symgbas.1 | ||
symgbas.2 | |||
Assertion | symgbasf |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | symgbas.1 | ||
2 | symgbas.2 | ||
3 | 1 2 | symgbasf1o | |
4 | f1of | ||
5 | 3 4 | syl |