#NEWLINE# def main( ) : #NEWLINE# #INDENT# x = Symbol ( 'x' ) #NEWLINE# y = Symbol ( 'y' ) #NEWLINE# mplot3d ( ( ( x ** 2 ) - ( y ** 2 ) ) , ( y , ( - 10.0 ) , 10.0 , 20 ) , ( y , ( - 10.0 ) , 10.0 , 20 ) )