Can we perform nested if-logic in computed fields?

We are attempting to add some required functionality for our users and need to perform nested if-statements in computed fields. How do we do this?

Example that we cannot make work:

A short text field. Syntax indented/format to make the logic a bit more readable.:

(Type == "Program Requirement")

    ?

    getFieldValue(ID, "Program Requirement Statement")

    :

    (

    (Type == "Product Requirement")

        ?

        getFieldValue(ID, "Product Requirement Statement")

        :

        getFieldValue(ID, "Synopsis")

    )

It addition... I appears that computed short text field has inconsisent results when it refers to a long text field with rich content. Sometimes the <-- MKS HTML> tags are showing up and sometimes not. How do we fix this problem?