sub_atom_icasechk/3

Availability:built-in

[semidet]sub_atom_icasechk(+Haystack, ?Start, +Needle)

True when Needle is a sub atom of Haystack starting at Start. The match is `half case insensitive', i.e., uppercase letters in Needle only match themselves, while lowercase letters in Needle match case insensitively. Start is the first 0-based offset inside Haystack where Needle matches.^{103This predicate replaces $apropos_match/2,
used by the help system, while extending it with locating the (first)
match and performing case insensitive prefix matching. We are still not
happy with the name and interface.}