I'm having a problem with the argument of a subroutine which I didn't write myself, but should be working as intended. I'm supposed to write my own subroutine named funcs(a,b,c). Then this subroutine that I got has funcs as one of it's arguments subr(a,b,c,funcs,..) and it says in the description of the subroutine that I must provide a subroutine funcs to make subr(a,b,c,funcs,..) work. The problem is when I don't declare funcs (Real/integer....) I get an error that funcs is not explicitly declared.. When I do declare funcs, i get an error that i 'attempt to call a non-subroutine'. Is there a way to pass my subroutine to the other subroutine?