reserve X,Y,Z,X1,X2,Y1,Y2 for set, x,y,z,t,x1,x2 for object,
  f,g,h,f1,f2,g1,g2 for Function;
reserve C,D,E for non empty set;
reserve c for Element of C,
  d for Element of D;
reserve f for Function of [:C,D:],E;

theorem
  f.(c,d) = ((curry' f).d).c
proof
  [c,d] in [:C,D:];
  then [c,d] in dom f by FUNCT_2:def 1;
  hence thesis by Th15;
end;
