I replied in detail to the child thread on it being impossible to
devise a formal grammar for Fortran before I saw this one (its
parent).
Of course one can write a grammar for Fortran using a formal system
such as BNF. It's just not going to be a well-behaved context-free
grammar such as one can do for C or Pascal, and you won't be able to
feed the grammar to lex and yacc, press a button, and have a compiler
pop out. Fortran was being devised at the same time that Chomsky, et.
al. were doing the research on formal languages. Essentially, Fortran
syntax was devised before computer scientists knew better. I suspect
COBOL has similar issues.
-Paul W.