Metamath Proof Explorer


Theorem xaddge0

Description: The sum of nonnegative extended reals is nonnegative. (Contributed by Mario Carneiro, 21-Aug-2015)

Ref Expression
Assertion xaddge0 A*B*0A0B0A+𝑒B

Proof

Step Hyp Ref Expression
1 0xr 0*
2 1 a1i A*B*0A0B0*
3 simplr A*B*0A0BB*
4 xaddcl A*B*A+𝑒B*
5 4 adantr A*B*0A0BA+𝑒B*
6 simprr A*B*0A0B0B
7 xaddlid B*0+𝑒B=B
8 3 7 syl A*B*0A0B0+𝑒B=B
9 simpll A*B*0A0BA*
10 simprl A*B*0A0B0A
11 xleadd1a 0*A*B*0A0+𝑒BA+𝑒B
12 2 9 3 10 11 syl31anc A*B*0A0B0+𝑒BA+𝑒B
13 8 12 eqbrtrrd A*B*0A0BBA+𝑒B
14 2 3 5 6 13 xrletrd A*B*0A0B0A+𝑒B