ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  df-relog Unicode version

Definition df-relog 12985
Description: Define the natural logarithm function. Defining the logarithm on complex numbers is similar to square root - there are ways to define it but they tend to make use of excluded middle. Therefore, we merely define logarithms on positive reals. See http://en.wikipedia.org/wiki/Natural_logarithm and https://en.wikipedia.org/wiki/Complex_logarithm. (Contributed by Jim Kingdon, 14-May-2024.)
Assertion
Ref Expression
df-relog  |-  log  =  `' ( exp  |`  RR )

Detailed syntax breakdown of Definition df-relog
StepHypRef Expression
1 clog 12983 . 2  class  log
2 ce 11383 . . . 4  class  exp
3 cr 7642 . . . 4  class  RR
42, 3cres 4548 . . 3  class  ( exp  |`  RR )
54ccnv 4545 . 2  class  `' ( exp  |`  RR )
61, 5wceq 1332 1  wff  log  =  `' ( exp  |`  RR )
Colors of variables: wff set class
This definition is referenced by:  dfrelog  12987  reeflog  12990
  Copyright terms: Public domain W3C validator