SYNOPSIS
    string norm_id (string id [, 0])
    string * norm_id (string id, 1)

DESCRIPTION
    The given <id> string is made lowercase, and sequences of multiple
    spaces are folded into just one space. The resulting string is
    returned.
    If a non-zero integer is given as second parameter, the result is not
    a string, but instead the normalized string exploded by the spaces.
    
    The function is used to normalize id-strings.

EXAMPLE
    norm_id("the   yellow Car  ") --> "the yellow car"
    norm_id("the   yellow Car  ", 0) --> "the yellow car"
    norm_id("the   yellow Car  ", 1) --> ({ "the", "yellow", "car" })

SEE ALSO
    gen_id_pattern(sefun), match_id(sefun)