pre (Initialized Unit Delay)

Returns value at previous step with initial value.

At each step, returns the value of the input flow at its previous step. Its first parameter is the first value of the result sequence.

Syntax

expr pre expr

Signatures

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

    In this operator 'T can be extended to a group

  2. Causality

    The output depends instantaneously on the first input.

  3. Initialization

    The resulting sequence has its first value defined if the first input has its first value defined.

  4. Clock

    Inputs and the output have the same clock.