VMS Help FORTRAN, Statements, IF  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Conditionally transfers control or executes a statement or block of
  statements.

  For each type of IF statement, the decision to transfer control or
  to execute the statement or block of statements is based on the
  evaluation of an expression within the IF statement.

  Additional Information (explode) :

• Arithmetic
• Logical
• Block