Metamath Proof Explorer


Theorem dmlogdmgm

Description: If A is in the continuous domain of the logarithm, then it is in the domain of the Gamma function. (Contributed by Mario Carneiro, 8-Jul-2017)

Ref Expression
Assertion dmlogdmgm A−∞0A

Proof

Step Hyp Ref Expression
1 eldifi A−∞0A
2 simpr A−∞0A0A0
3 2 nn0ge0d A−∞0A00A
4 1 adantr A−∞0A0A
5 2 nn0red A−∞0A0A
6 4 5 negrebd A−∞0A0A
7 eqid −∞0=−∞0
8 7 ellogdm A−∞0AAA+
9 8 simprbi A−∞0AA+
10 9 imp A−∞0AA+
11 6 10 syldan A−∞0A0A+
12 11 rpgt0d A−∞0A00<A
13 6 lt0neg2d A−∞0A00<AA<0
14 12 13 mpbid A−∞0A0A<0
15 0red A−∞0A00
16 5 15 ltnled A−∞0A0A<0¬0A
17 14 16 mpbid A−∞0A0¬0A
18 3 17 pm2.65da A−∞0¬A0
19 eldmgm AA¬A0
20 1 18 19 sylanbrc A−∞0A