Executable GOTO statements:
GOTO snr1 - ordinary GOTO statement (jumps to the statement with
number snr1)
? GOTO (snr1, snr2, snr3), integer_expression - conditional GOTO statement. If the integer expression is 1, 2 or 3, execution jumps to statement number snr1, snr2 or snr3 (an arbitrary number of statement numbers snr are permitted).
??GOTO statement_number_variable, (snr1, snr2, snr3)
- an assigned GOTO statement, jumps to the statement
number that equals the statement
number variable (an arbitrary number of
statement numbers snr are permitted).
??GOTO statement_number_variable
- this is an assigned ordinary GOTO statement, it is a
combination of the first one, GOTO snr1, and
previous one, GOTO statement_number_variable without
a list of permitted alternatives.
??ASSIGN statement_number TO statement_number_variable
- statement number variables can not be assigned with
an ordinary assignment of the type (integer
variable = integer expression), it has to be
done with the ASSIGN statement. The statement
number variable can then be used for an assigned
GOTO statement and in the ordinary GOTO statement
and also in connection with FORMAT.
? IF (numerical_expression) snr1, snr2, snr3
- arithmetical IF-statement, jumps to statement number
snr1 if the expression is negative,
snr2 if the expression is zero,
snr3 if the expression is positive
refer: http://www.nsc.liu.se/~boein/f77to90/a2.html#section4
