Description: Theorem 19.38 of Margaris p. 90. The converse holds under non-freeness conditions, see 19.38a and 19.38b . (Contributed by NM, 12-Mar-1993) Allow a shortening of 19.21t . (Revised by Wolf Lammen, 2-Jan-2018)
Ref | Expression | ||
---|---|---|---|
Assertion | 19.38 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | alnex | ||
2 | pm2.21 | ||
3 | 2 | alimi | |
4 | 1 3 | sylbir | |
5 | ala1 | ||
6 | 4 5 | ja |