Operators: Binary

The following are the binary operators:

• logical AND
  This is implicit, and has no explicit representation in the condition name.
• logical OR, represented by the symbol | (Hex 4f)

Where an expression contains conditions connected by an AND operator, both must be present in the IOA Conditions File for the expression to be "True".

An expression that contains conditions connected by an OR operator is "True" if either expression is present in the IOA Conditions File.

Because logical OR operators are expressed as part of the condition name,

• all conditions connected by the logical OR must specify the OR symbol in their condition name

  This means that, for example, expressions of the form

  A    |B

  must not be specified because their meaning is unclear, even though they will not be syntactically rejected. In reality, because condition name A does not have an OR symbol attached to it, no logical OR connection exists between A and B, and the OR symbol attached to condition name B is ignored. The correct way to specify "Condition A OR Condition B" is

  (|A    |B)

• all condition names that specify an OR symbol are processed first, before those specifying an AND symbol

  This has the effect of creating implicit parentheses among the terms of the expression (explained under "Operators: Group" below); the terms of the expression may also be rearranged.

  For example, the expression

  |B    |C    D    |E

  is processed as if the expression had been

  ( |B    |C    |E )    D