code: public EquivalentTerm convert(Term t) {
          if (t == null) return null;
          return termCvtr.convert(t);
      }
docs: Returns an {@link EquivalentTerm} converted from the supplied
  {@link Term}.
  
  @param t {@link Term}; may be null
  @return {@link EquivalentTerm}; null if {@code t} was null