| Step |
Hyp |
Ref |
Expression |
| 1 |
|
frlmfibas.f |
|- F = ( R freeLMod I ) |
| 2 |
|
frlmfibas.n |
|- N = ( Base ` R ) |
| 3 |
|
elfrlmbasn0.b |
|- B = ( Base ` F ) |
| 4 |
1 2 3
|
frlmbasf |
|- ( ( I e. V /\ X e. B ) -> X : I --> N ) |
| 5 |
4
|
ex |
|- ( I e. V -> ( X e. B -> X : I --> N ) ) |
| 6 |
|
f0dom0 |
|- ( X : I --> N -> ( I = (/) <-> X = (/) ) ) |
| 7 |
6
|
biimprd |
|- ( X : I --> N -> ( X = (/) -> I = (/) ) ) |
| 8 |
7
|
necon3d |
|- ( X : I --> N -> ( I =/= (/) -> X =/= (/) ) ) |
| 9 |
8
|
com12 |
|- ( I =/= (/) -> ( X : I --> N -> X =/= (/) ) ) |
| 10 |
5 9
|
sylan9 |
|- ( ( I e. V /\ I =/= (/) ) -> ( X e. B -> X =/= (/) ) ) |