{{alias}}( value )
    Tests if an input value is a BLAS matrix triangle.

    Parameters
    ----------
    value: any
        Value to test.

    Returns
    -------
    bool: boolean
        Boolean indicating if an input value is a matrix triangle.

    Examples
    --------
    > var bool = {{alias}}( 'lower' )
    true
    > bool = {{alias}}( 'upper' )
    true
    > bool = {{alias}}( '' )
    false
    > bool = {{alias}}( 'beep' )
    false

    See Also
    --------