Theorem breqtri 4007

Description: Substitution of equal classes into a binary relation. (Contributed by NM, 5-Aug-1993.)

Hypotheses

Ref	Expression
breqtr.1	⊢ 𝐴𝑅𝐵
breqtr.2	⊢ 𝐵 = 𝐶

Assertion

Ref	Expression
breqtri	⊢ 𝐴𝑅𝐶

Proof of Theorem breqtri

Step	Hyp	Ref	Expression
1		breqtr.1	. 2 ⊢ 𝐴𝑅𝐵
2		breqtr.2	. . 3 ⊢ 𝐵 = 𝐶
3	2	breq2i 3990	. 2 ⊢ (𝐴𝑅𝐵 ↔ 𝐴𝑅𝐶)
4	1, 3	mpbi 144	1 ⊢ 𝐴𝑅𝐶

Syntax hints:   = wceq 1343   class class class wbr 3982

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 699  ax-5 1435  ax-7 1436  ax-gen 1437  ax-ie1 1481  ax-ie2 1482  ax-8 1492  ax-10 1493  ax-11 1494  ax-i12 1495  ax-bndl 1497  ax-4 1498  ax-17 1514  ax-i9 1518  ax-ial 1522  ax-i5r 1523  ax-ext 2147

This theorem depends on definitions:  df-bi 116  df-3an 970  df-tru 1346  df-nf 1449  df-sb 1751  df-clab 2152  df-cleq 2158  df-clel 2161  df-nfc 2297  df-v 2728  df-un 3120  df-sn 3582  df-pr 3583  df-op 3585  df-br 3983

This theorem is referenced by:  breqtrri  4009  3brtr3i  4011  le9lt10  9348  9lt10  9452  sqrt2gt1lt2  10991  trireciplem  11441  cos1bnd  11700  cos2bnd  11701  cos01gt0  11703  sin4lt0  11707  z4even  11853  coseq00topi  13396  sincos4thpi  13401  lgsdir2lem2  13570  lgsdir2lem3  13571  ex-fl  13606