dim(x,y) returns the difference x-y if the result is positive; otherwise returns zero.
FORTRAN 77 and later
result = dim(x, y)
x - The type shall be integer or realy - The type shall be the same type and kind as x.The return value is of type integer or real.
program test_dim
integer :: i
real(8) :: x
i = dim(4, 15)
x = dim(4.345_8, 2.111_8)
print *, i
print *, x
end program test_dim