rdf_litindex:rdf_literal

True when Index is a literal map containing the index of Type. Type is one of:

token: Tokens are basically words of literal values. See rdf_tokenize_literal/2. The token map maps tokens to full literal texts.
stem: Index of stemmed tokens. If the language is available, the tokens are stemmed using the matching snowball stemmer. The stem map maps stemmed to full tokens.
metaphone: Phonetic index of tokens. The metaphone map maps phonetic keys to tokens.