Owner`s manual

65
• Logical operation
Logical operation
The task of giving YES
or ON results, by judgment, are not few in computers. Here
let
us consider some logical expressions used to judge some conditions. The logical
operators
NOT, AND, OR and XOR are used in logical expressions.
CD X AND Y (logical product = and)
AND means X moreover Y
XY
X and Y
1 1 1
1
0 0
0
1 0
0 0 0
® NOT X (negation = not)
Means that it
is not X
NOT X
o
® X OR Y (logical addition = inclusive or)
OR means either X or Y
XY XORY
1 1
1
1
0
1
0
1 1
0
0 0
@ X XOR Y (Exclusive logical addition =
exclusive or)
Means X and
Y are not equal
XY XXORY
1 1
0
1 0
1
0 1
1
0 0
0
The logical operation is usually used in IF - THEN - ELSE command, explained
before. For instance, it
is used as follows:
• IF -30<X AND Y>20 THEN 120 ELSE 100
(The meaning above is: if the X value is -30<X moreover Y>29 go to line number
120, if not jump to line 100)
• IF -30<X OR Y>20 THEN 10 ELSE 100
(The meaning above is: if the X value is -30<X or Y>20 to to line number 120, if
not jump to line
100).