ISO Pascal reference manual

Chapter 5
product := this * that;
*ERROR 11 -- a semicolon is required here
As you can see, the error is not reported at the exact point at which the
mistake was made.
It is also common for errors in one part of a program to cause consequential -
errors in other parts. For example, consider the following program:
PROGRAM test(output);
VAR sum.difference:integer; (error . should be ,)
BEGIN
END.
sum := 12 + 7;
difference := 12 - 7;
Because there is an error in the declarations of 'sum' and 'difference', the
compiler will report spurious errors when they are used. The actual errors
generated by this program are:
2 VAR sum.difference:integer; (error . should be ,1
*ERROR 15 -- ':' is required here
5 difference := 12 - 7;
*ERROR 23 -- DIFFERENCE has not been declared
Note that even though the compiler has detected the error in line 2 at the
correct place, it has made the wrong guess as to the cause. A statement of
the form:
VAR sum:integer;
was expected.
If you cannot understand why an error has been reported on a particular
statement, it may be that an error exists earlier in the program, and the
error message is a result of a previous mistake.
Appendix A contains descriptions of error messages which may be
produced by the compiler. Each description is accompanied by one or more
complete (albeit incorrect) programs which demonstrate the fault, or the
28 Pascal Issue 1