This function converts this Clause to an ordinary first-order Sentence, which
is either TruthValue.FALSE for the empty Clause, a Literal for a unit Clause, or
a disjunction of the Literals in this Clause.
This function returns a printable representation of this AnonymousSymbol
which is the type of this AnonymousSymbol followed by the index (without
space).
This function returns a printable representation of this NamedSymbol
which is the URI for its NameSpace followed by the hash character
followed by the name of the symbol.
This function returns a printable representation of this NamedSymbol
which is an abbreviation for the NameSpace from the given Map followed by
the colon character followed by the name of the symbol.