HP 9835A Programming Manual page 92

76
Assembly Language Fundamentals
An expression is a list of elements each pair of which is separated by one of the following
operators -
·:1':·
meaning addition, subtraction, division, and multiplication, respectively, as in BASIC.
The result of an expression is either absolute or relocatable depending upon the following
rules:
An absolute expression is any expression which contains
~
• Only absolute elements.
• An even number of relocatable elements, paired in sequence and by sign (Le., for each
relocatable element there is another relocatable element adjacent to it, of opposite sign).
These pairs may be in combination with absolute elements.
A relocatable expression is any expression which contains -
• An odd number of relocatable elements, paired in sequence and by sign, except the last,
which must be positive.
• An odd number of relocatable elements, as above, in combination with any number of
absolute elements.
Any combination of absolute or relocatable elements which does not result in either an abso-
lute or relocatable value, by the rules above, results in an error.
These rules and the rules for using
::-1<
and . . . . . . can be summarized as -
The expression is - The type is- Example
absolute
±
absolute absolute
absolute
+
relocatable relocatable
relocatable
±
absolute relocatable
relocatable - relocatable absolute
relocatable
+
relocatable
error
absolute - relocatable error
absolute
*
absolute absolute
absolute / absolute absolute
absolute
*
relocatable error
relocatable
*
absolute error
absolute / relocatable
error
relocatable / absolute error