Metamath Proof Explorer


Theorem lnfnsubi

Description: Subtraction property for a linear Hilbert space functional. (Contributed by NM, 13-Feb-2006) (New usage is discouraged.)

Ref Expression
Hypothesis lnfnl.1 T LinFn
Assertion lnfnsubi A B T A - B = T A T B

Proof

Step Hyp Ref Expression
1 lnfnl.1 T LinFn
2 neg1cn 1
3 1 lnfnaddmuli 1 A B T A + -1 B = T A + -1 T B
4 2 3 mp3an1 A B T A + -1 B = T A + -1 T B
5 hvsubval A B A - B = A + -1 B
6 5 fveq2d A B T A - B = T A + -1 B
7 1 lnfnfi T :
8 7 ffvelrni A T A
9 7 ffvelrni B T B
10 mulm1 T B -1 T B = T B
11 10 oveq2d T B T A + -1 T B = T A + T B
12 11 adantl T A T B T A + -1 T B = T A + T B
13 negsub T A T B T A + T B = T A T B
14 12 13 eqtr2d T A T B T A T B = T A + -1 T B
15 8 9 14 syl2an A B T A T B = T A + -1 T B
16 4 6 15 3eqtr4d A B T A - B = T A T B