Metamath Proof Explorer


Theorem normlem4

Description: Lemma used to derive properties of norm. Part of Theorem 3.3(ii) of Beran p. 97. (Contributed by NM, 29-Jul-1999) (New usage is discouraged.)

Ref Expression
Hypotheses normlem1.1 S
normlem1.2 F
normlem1.3 G
normlem2.4 B = S F ih G + S G ih F
normlem3.5 A = G ih G
normlem3.6 C = F ih F
normlem4.7 R
normlem4.8 S = 1
Assertion normlem4 F - S R G ih F - S R G = A R 2 + B R + C

Proof

Step Hyp Ref Expression
1 normlem1.1 S
2 normlem1.2 F
3 normlem1.3 G
4 normlem2.4 B = S F ih G + S G ih F
5 normlem3.5 A = G ih G
6 normlem3.6 C = F ih F
7 normlem4.7 R
8 normlem4.8 S = 1
9 1 2 3 7 8 normlem1 F - S R G ih F - S R G = F ih F + S R F ih G + S R G ih F + R 2 G ih G
10 1 2 3 4 5 6 7 normlem3 A R 2 + B R + C = F ih F + S R F ih G + S R G ih F + R 2 G ih G
11 9 10 eqtr4i F - S R G ih F - S R G = A R 2 + B R + C