Metamath Proof Explorer


Theorem coinflipuniv

Description: The universe of our coin-flip probability is { H , T } . (Contributed by Thierry Arnoux, 15-Jan-2017)

Ref Expression
Hypotheses coinflip.h
|- H e. _V
coinflip.t
|- T e. _V
coinflip.th
|- H =/= T
coinflip.2
|- P = ( ( # |` ~P { H , T } ) oFC / 2 )
coinflip.3
|- X = { <. H , 1 >. , <. T , 0 >. }
Assertion coinflipuniv
|- U. dom P = { H , T }

Proof

Step Hyp Ref Expression
1 coinflip.h
 |-  H e. _V
2 coinflip.t
 |-  T e. _V
3 coinflip.th
 |-  H =/= T
4 coinflip.2
 |-  P = ( ( # |` ~P { H , T } ) oFC / 2 )
5 coinflip.3
 |-  X = { <. H , 1 >. , <. T , 0 >. }
6 1 2 3 4 5 coinflipspace
 |-  dom P = ~P { H , T }
7 6 unieqi
 |-  U. dom P = U. ~P { H , T }
8 unipw
 |-  U. ~P { H , T } = { H , T }
9 7 8 eqtri
 |-  U. dom P = { H , T }