def substitute(lhs,rhs,term):
global substitutions
substitutions.clear()
if match_terms(lhs,term):
term = Rule(rhs.string)
term = substitute_helper(term)
return True,term
if term.object_type=='bfun':
status1,result1 = substitute(lhs,rhs,term.parameter_1)
if (status1):
term.parameter_1 = result1
status2,result2 = substitute(lhs,rhs,term.parameter_2)
if (status2):
term.parameter_2 = result2
if (status1 or status2):
term.string=term.function_type + "(" + term.parameter_1.string + "," + term.parameter_2.string +")"
return True,term
if term.object_type=='ufun':
status,result=substitute(lhs,rhs,term.parameter_1)
if (status == True):
term.parameter_1=result
term.string=term.function_type+"("+result.string+")"
return True,term
return False,term
