let X, Y be non empty set ; for A being Subset of X
for B being Subset of Y
for y being Element of Y
for f being PartFunc of [:X,Y:],REAL st dom f = [:A,B:] holds
( ( y in B implies ( dom (ProjPMap2 ((R_EAL f),y)) = A & dom (ProjPMap2 (|.(R_EAL f).|,y)) = A ) ) & ( not y in B implies ( dom (ProjPMap2 ((R_EAL f),y)) = {} & dom (ProjPMap2 (|.(R_EAL f).|,y)) = {} ) ) )
let A be Subset of X; for B being Subset of Y
for y being Element of Y
for f being PartFunc of [:X,Y:],REAL st dom f = [:A,B:] holds
( ( y in B implies ( dom (ProjPMap2 ((R_EAL f),y)) = A & dom (ProjPMap2 (|.(R_EAL f).|,y)) = A ) ) & ( not y in B implies ( dom (ProjPMap2 ((R_EAL f),y)) = {} & dom (ProjPMap2 (|.(R_EAL f).|,y)) = {} ) ) )
let B be Subset of Y; for y being Element of Y
for f being PartFunc of [:X,Y:],REAL st dom f = [:A,B:] holds
( ( y in B implies ( dom (ProjPMap2 ((R_EAL f),y)) = A & dom (ProjPMap2 (|.(R_EAL f).|,y)) = A ) ) & ( not y in B implies ( dom (ProjPMap2 ((R_EAL f),y)) = {} & dom (ProjPMap2 (|.(R_EAL f).|,y)) = {} ) ) )
let y be Element of Y; for f being PartFunc of [:X,Y:],REAL st dom f = [:A,B:] holds
( ( y in B implies ( dom (ProjPMap2 ((R_EAL f),y)) = A & dom (ProjPMap2 (|.(R_EAL f).|,y)) = A ) ) & ( not y in B implies ( dom (ProjPMap2 ((R_EAL f),y)) = {} & dom (ProjPMap2 (|.(R_EAL f).|,y)) = {} ) ) )
let f be PartFunc of [:X,Y:],REAL; ( dom f = [:A,B:] implies ( ( y in B implies ( dom (ProjPMap2 ((R_EAL f),y)) = A & dom (ProjPMap2 (|.(R_EAL f).|,y)) = A ) ) & ( not y in B implies ( dom (ProjPMap2 ((R_EAL f),y)) = {} & dom (ProjPMap2 (|.(R_EAL f).|,y)) = {} ) ) ) )
assume
dom f = [:A,B:]
; ( ( y in B implies ( dom (ProjPMap2 ((R_EAL f),y)) = A & dom (ProjPMap2 (|.(R_EAL f).|,y)) = A ) ) & ( not y in B implies ( dom (ProjPMap2 ((R_EAL f),y)) = {} & dom (ProjPMap2 (|.(R_EAL f).|,y)) = {} ) ) )
then A1:
dom (R_EAL f) = [:A,B:]
by MESFUNC5:def 7;
then A2:
dom |.(R_EAL f).| = [:A,B:]
by MESFUNC1:def 10;
hence
( y in B implies ( dom (ProjPMap2 ((R_EAL f),y)) = A & dom (ProjPMap2 (|.(R_EAL f).|,y)) = A ) )
by A1, Th26; ( not y in B implies ( dom (ProjPMap2 ((R_EAL f),y)) = {} & dom (ProjPMap2 (|.(R_EAL f).|,y)) = {} ) )
assume
not y in B
; ( dom (ProjPMap2 ((R_EAL f),y)) = {} & dom (ProjPMap2 (|.(R_EAL f).|,y)) = {} )
hence
( dom (ProjPMap2 ((R_EAL f),y)) = {} & dom (ProjPMap2 (|.(R_EAL f).|,y)) = {} )
by A1, A2, Th26; verum