Metamath Proof Explorer


Theorem congadd

Description: If two pairs of numbers are componentwise congruent, so are their sums. (Contributed by Stefan O'Rear, 1-Oct-2014)

Ref Expression
Assertion congadd ABCDEABCADEAB+D-C+E

Proof

Step Hyp Ref Expression
1 simpl1 ABCDEA
2 zsubcl BCBC
3 2 3adant1 ABCBC
4 3 adantr ABCDEBC
5 zsubcl DEDE
6 5 adantl ABCDEDE
7 dvds2add ABCDEABCADEABC+D-E
8 1 4 6 7 syl3anc ABCDEABCADEABC+D-E
9 8 3impia ABCDEABCADEABC+D-E
10 simpl2 ABCDEB
11 10 zcnd ABCDEB
12 zcn DD
13 12 ad2antrl ABCDED
14 simpl3 ABCDEC
15 14 zcnd ABCDEC
16 zcn EE
17 16 ad2antll ABCDEE
18 11 13 15 17 addsub4d ABCDEB+D-C+E=BC+D-E
19 18 3adant3 ABCDEABCADEB+D-C+E=BC+D-E
20 9 19 breqtrrd ABCDEABCADEAB+D-C+E