SIMSCRIPT II.5 Programming Language

SIMSCRIPT II.5 Programming Language
1. I equals J is true or false depending on the values I, J
2. I equals Q is always false
3. M + N is positive is always true
4. M + T is positive is true or false depending on the values M, T
5. I > 0 and J > 0 is always true
6. I > 0 or R > 0 is always true
7. I eq J and Z eq 0 is true if I equals J, and false otherwise
8. I eq J or Z eq 0 is always true
9. I = J and K > N and R = S is true if all three conditions are true, and
false otherwise; it is evaluated as ((I =
J) and (K > N) and (R = S))
10. I = J or K > N or R = S is true if any one of the three conditions
is true; it is false only if all are false
11. I = J and K > N or R = S is true if either of the two conditions
12. Z is zero and (I < 0 or S < 0) and Q = T is true if Q = T
13. Z is zero and (I > 0 or S < 0) and Q = T is true if Q = T
around the or is true; it is evaluated as
(I = J and K > N) or (R = S)
14. J< K and (I = Q or S < 0) and J + K < I is true if J < K and J + K < I
When a statement containing a compound logical expression is executed, it does not always follow
that all logical conditions in the statement are examined. For example, in the segment:
if X > Y**2 and COUNT > N
add ...
always
both logical expressions have to be true for the add statement to be executed. If the first logical
expression (X > Y**2) is false, there is no need to evaluate the second (COUNT > N), as the compound
logical expression X > Y**2 and COUNT > N can never be true regardless of the values of COUNT
and N. In normal circumstances, the fact that all the parts of a compound logical expression may
not be evaluated each time will cause no difficulty.
It should be noted that compound logical expressions formed using the logical operator and may
be written in an alternative way. Using e to represent an arithmetic expression and R to represent a
relational operator, such compound logical expressions may be written as:
Form
e R e
e R e R e
Example
1 < X
1 < X < N
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