Metamath Proof Explorer


Theorem subsub23d

Description: Swap subtrahend and result of subtraction. (Contributed by Glauco Siliprandi, 11-Dec-2019)

Ref Expression
Hypotheses subsub23d.1 φ A
subsub23d.2 φ B
subsub23d.3 φ C
Assertion subsub23d φ A B = C A C = B

Proof

Step Hyp Ref Expression
1 subsub23d.1 φ A
2 subsub23d.2 φ B
3 subsub23d.3 φ C
4 subsub23 A B C A B = C A C = B
5 1 2 3 4 syl3anc φ A B = C A C = B