pre (Unit Delay)

Returns value at previous step.

At each step, returns the value of the input flow at its previous step. The first value of the resulting sequence is not defined.

Syntax

pre expr

Signatures

  1. Type 
    ('T) returns ('T)

    In this operator 'T can be extended to a group

  2. Causality

    The output does not depend on the input.

  3. Initialization

    The first value of the result sequence is not defined.

  4. Clock

    The input and the output have the same clock.