#NEWLINE# def _vsids_clause_added( self , cls ) : #NEWLINE# #INDENT# 'Handle the addition of a new clause for the VSIDS heuristic.\n\n        Examples\n        ========\n\n        >>> from sympy.logic.algorithms.dpll2 import SATSolver\n        >>> l = SATSolver([set([2, -3]), set([1]), set([3, -3]), set([2, -2]),\n        ... set([3, -2])], set([1, 2, 3]), set([]))\n\n        >>> l.num_learned_clauses\n        0\n        >>> l.lit_scores\n        {-3: -2.0, -2: -2.0, -1: 0.0, 1: 0.0, 2: -2.0, 3: -2.0}\n\n        >>> l._vsids_clause_added(set([2, -3]))\n\n        >>> l.num_learned_clauses\n        1\n        >>> l.lit_scores\n        {-3: -1.0, -2: -2.0, -1: 0.0, 1: 0.0, 2: -1.0, 3: -2.0}\n        ' #NEWLINE# self . num_learned_clauses += 1 #NEWLINE# for lit in cls : #NEWLINE# #INDENT# self . lit_scores [ lit ] += 1