Description: Distribution of multiplication over subtraction. Theorem I.5 of Apostol p. 18. (Contributed by Mario Carneiro, 27-May-2016)
Ref | Expression | ||
---|---|---|---|
Hypotheses | mulm1d.1 | |
|
mulnegd.2 | |
||
subdid.3 | |
||
Assertion | subdid | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | mulm1d.1 | |
|
2 | mulnegd.2 | |
|
3 | subdid.3 | |
|
4 | subdi | |
|
5 | 1 2 3 4 | syl3anc | |