Can a mathematical function like sin() be redefined, in Fortran, C or Java code, while preserving the default behavior of other mathematical functions like cos()? Or can another function named sin() but that accepts different argument types be defined in addition to the built-in sin()? I am interested in general features of these languages (I am thinking of applications like the implementation of non-usual number algebras).

I tried to define a sin() function in a Fortran 95 program, but the intrinsic sin() function was called instead… Is there a way around this? what about C and Java?