Metamath Proof Explorer


Theorem hvsubdistr1

Description: Scalar multiplication distributive law for subtraction. (Contributed by NM, 19-May-2005) (New usage is discouraged.)

Ref Expression
Assertion hvsubdistr1 A B C A B - C = A B - A C

Proof

Step Hyp Ref Expression
1 neg1cn 1
2 hvmulcl 1 C -1 C
3 1 2 mpan C -1 C
4 ax-hvdistr1 A B -1 C A B + -1 C = A B + A -1 C
5 3 4 syl3an3 A B C A B + -1 C = A B + A -1 C
6 hvmulcom A 1 C A -1 C = -1 A C
7 1 6 mp3an2 A C A -1 C = -1 A C
8 7 oveq2d A C A B + A -1 C = A B + -1 A C
9 8 3adant2 A B C A B + A -1 C = A B + -1 A C
10 5 9 eqtrd A B C A B + -1 C = A B + -1 A C
11 hvsubval B C B - C = B + -1 C
12 11 3adant1 A B C B - C = B + -1 C
13 12 oveq2d A B C A B - C = A B + -1 C
14 hvmulcl A B A B
15 14 3adant3 A B C A B
16 hvmulcl A C A C
17 16 3adant2 A B C A C
18 hvsubval A B A C A B - A C = A B + -1 A C
19 15 17 18 syl2anc A B C A B - A C = A B + -1 A C
20 10 13 19 3eqtr4d A B C A B - C = A B - A C