Description: Distribution of negative over subtraction. (Contributed by NM, 6-Aug-1999)
Ref | Expression | ||
---|---|---|---|
Hypotheses | negidi.1 | |
|
pncan3i.2 | |
||
Assertion | negsubdii | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | negidi.1 | |
|
2 | pncan3i.2 | |
|
3 | 2 | negcli | |
4 | 1 3 | negdii | |
5 | 1 2 | negsubi | |
6 | 5 | negeqi | |
7 | 2 | negnegi | |
8 | 7 | oveq2i | |
9 | 4 6 8 | 3eqtr3i | |