ISO Pascal reference manual

*Execution error -- x MOD is not permitted
The definition of the operator MOD states that it shall be an error if in an
expression of the form: i MOD j the value of j is less than or equal to zero.
PROGRAM error(output);
VAR i, j, k : integer;
BEGIN
i := 123;
j := -1;
k := i MOD j; (wrong}
writeln('Error not detected');
END.
*Execution error -- zero or negative argument for logarithm
The mathematical function LN (logarithm to base 'e') is not defined for
arguments less than or equal to zero.
PROGRAM error(output);
VAR j : integer;
: real;
BEGIN
FOR j := 5 DOWNTO -5 DO
:= LN(j); (should fail)
writeln('Error not detected');
END.
*Execution error -- negative argument for square root
The mathemetical function SQRT (square root) is not defined for
arguments less than zero.
PROGRAM error(output);
VAR j : integer;
r : real;
BEGIN
FOR j := 5 DOWNTO -5 DO
r := SQRT(j); (should fail}
writeln('Error not detected');
END.
104 Pascal Issue 1