A procedure is run by calling it. To call it, a programmer uses the procedure name and includes any parameters (values) that the procedure needs, for example: SUBROUTINE f_TO_c(temperature_in_f) ...
< argseq > is a sequence of varaible names, possibly null, seperated by commas ','. These variables are the arguments to the procedure. < nseq > is a sequence of varaible names, seperated by commas ', ...