Conditional expression

The form of a conditional expression is as follows:

{Condition} ? [expression1] : [expression2]

Where:

Condition is:

• an object that acquires a value of Boolean type
• a logical expression enclosed in any type of brackets - { }, ( ) or [ ]

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The result value of an expression that is evaluated is the result of the conditional expression. Just the expression, for which the Condition is met, is evaluated.

Warning:
If a function, that uses its previous internal state (e.g. %PrevV, %Integral,...) for evaluation, is included in the expression that has not been evaluated, the internal state is not correct!

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The task is to indicate the state , when the water level (the object Water_level) in the cistern falls under the minimum (the object Minimum).

We define a new eval tag called Low_level of logical type, which value is determined by the expression:

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If the arithmetical expression {Water_level < Minimum} is true, then the value of the object Low_level is TRUE, otherwise, the value is FALSE. The object Low_level is to be evaluated if a change of the input objects occurs (i.e. when Water_level or Minimum has changed).

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