Metamath Proof Explorer


Theorem leopadd

Description: The sum of two positive operators is positive. Exercise 1(i) of Retherford p. 49. (Contributed by NM, 25-Jul-2006) (New usage is discouraged.)

Ref Expression
Assertion leopadd THrmOpUHrmOp0hopopT0hopopU0hopopT+opU

Proof

Step Hyp Ref Expression
1 r19.26 x0Txihx0Uxihxx0Txihxx0Uxihx
2 hmopre THrmOpxTxihx
3 hmopre UHrmOpxUxihx
4 addge0 TxihxUxihx0Txihx0Uxihx0Txihx+Uxihx
5 4 ex TxihxUxihx0Txihx0Uxihx0Txihx+Uxihx
6 2 3 5 syl2an THrmOpxUHrmOpx0Txihx0Uxihx0Txihx+Uxihx
7 6 anandirs THrmOpUHrmOpx0Txihx0Uxihx0Txihx+Uxihx
8 hmopf THrmOpT:
9 hmopf UHrmOpU:
10 8 9 anim12i THrmOpUHrmOpT:U:
11 hosval T:U:xT+opUx=Tx+Ux
12 11 oveq1d T:U:xT+opUxihx=Tx+Uxihx
13 12 3expa T:U:xT+opUxihx=Tx+Uxihx
14 ffvelcdm T:xTx
15 14 adantlr T:U:xTx
16 ffvelcdm U:xUx
17 16 adantll T:U:xUx
18 simpr T:U:xx
19 ax-his2 TxUxxTx+Uxihx=Txihx+Uxihx
20 15 17 18 19 syl3anc T:U:xTx+Uxihx=Txihx+Uxihx
21 13 20 eqtrd T:U:xT+opUxihx=Txihx+Uxihx
22 10 21 sylan THrmOpUHrmOpxT+opUxihx=Txihx+Uxihx
23 22 breq2d THrmOpUHrmOpx0T+opUxihx0Txihx+Uxihx
24 7 23 sylibrd THrmOpUHrmOpx0Txihx0Uxihx0T+opUxihx
25 24 ralimdva THrmOpUHrmOpx0Txihx0Uxihxx0T+opUxihx
26 1 25 biimtrrid THrmOpUHrmOpx0Txihxx0Uxihxx0T+opUxihx
27 leoppos THrmOp0hopopTx0Txihx
28 leoppos UHrmOp0hopopUx0Uxihx
29 27 28 bi2anan9 THrmOpUHrmOp0hopopT0hopopUx0Txihxx0Uxihx
30 hmops THrmOpUHrmOpT+opUHrmOp
31 leoppos T+opUHrmOp0hopopT+opUx0T+opUxihx
32 30 31 syl THrmOpUHrmOp0hopopT+opUx0T+opUxihx
33 26 29 32 3imtr4d THrmOpUHrmOp0hopopT0hopopU0hopopT+opU
34 33 imp THrmOpUHrmOp0hopopT0hopopU0hopopT+opU