question: like common lisp first ; car of a pair , or null for anything else . concode_field_sep Boolean FALSE concode_elem_sep Boolean TRUE concode_elem_sep Double ONE concode_elem_sep Double ZERO concode_field_sep char[] listToString concode_elem_sep String sym concode_elem_sep Double num concode_elem_sep double num concode_elem_sep boolean eqv concode_elem_sep Object error concode_elem_sep Object second concode_elem_sep Object setFirst concode_elem_sep Object[] vec concode_elem_sep Object setRest concode_elem_sep Pair vectorToList concode_elem_sep Object write concode_elem_sep Pair cons concode_elem_sep Object rest concode_elem_sep Object listStar concode_elem_sep InputPort inPort concode_elem_sep int length concode_elem_sep Object[] listToVector concode_elem_sep char chr concode_elem_sep Character chr concode_elem_sep PrintWriter outPort concode_elem_sep Pair list concode_elem_sep Pair list concode_elem_sep Object reverse concode_elem_sep char[] str concode_elem_sep boolean equal concode_elem_sep Object p concode_elem_sep Object p concode_elem_sep Object warn concode_elem_sep Boolean truth concode_elem_sep boolean truth concode_elem_sep Object third concode_elem_sep void stringify concode_elem_sep String stringify concode_elem_sep String stringify
target: Object function ( Object arg0 ) { return ( arg0 instanceof Pair ) ? ( ( Pair ) arg0 ) . first : null ; }