Hi,
These two commands fail to give the same outputs. > sage: f = x-x+y; f, f(1) > (y,1) > sage: f = x+y-x; f, f(1) > (y,y) Here's another example. > sage: f = x-x+y-x; f, f(1,0) > (y - x, -1) > sage: f = x+y-x-x; f, f(1,0) > (y - x, y - 1) The bug stems from sage.calculus.SymbolicArithmetic.__call__(). The problem is that f.variables() relies on the simplified expression, while f.__call__() uses the pre-simplified expression. > try: > op_vars = op.variables() > if len(op_vars) == 0: > if len(args) != 0: > new_ops.append( op(args[0]) ) > else: > new_ops.append( op ) > continue > else: > indices = filter(lambda i: i < len(args), map(variables.index, > op_vars)) > if len(indices) == 0: > new_ops.append( op ) > else: > new_ops.append( op(*[args[i] for i in indices]) ) > except ValueError: > new_ops.append( op ) Paisa --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
