scheme :: BORSUK_6:sch 1
ExFunc3CondD{ F1() -> non empty set , P1[ set ], P2[ set ], P3[ set ], F2( set ) -> set , F3( set ) -> set , F4( set ) -> set } :
ex f being Function st
( dom f = F1() & ( for c being Element of F1() holds
( ( P1[c] implies f . c = F2(c) ) & ( P2[c] implies f . c = F3(c) ) & ( P3[c] implies f . c = F4(c) ) ) ) )
provided
A1: for c being Element of F1() holds
( ( P1[c] implies not P2[c] ) & ( P1[c] implies not P3[c] ) & ( P2[c] implies not P3[c] ) ) and
A2: for c being Element of F1() holds
( P1[c] or P2[c] or P3[c] )