def notify(msg):
    _.notify(msg)
def ask(msg):
    return _.ask(msg)
def diff(fun,var):
    return _.diff(fun,var)
def integrate(fun,var):
    return _.integrate(fun,var)
def rad(num):
    return _.rad(num)
def deg(num):
    return _.deg(num)
def subs(fun,var):
    return _.subs(fun,var)
def plot():
    _.plot()
def plot(fun):
    _.plot(fun)
def plotname(fun):
    _.plotname(fun)
def plotname():
    return _.plotname()
def xlim(min,max):
    _.xlim(min,max)
def plotclr():
    _.plotclr()
def drawdot(x, y):
    _.drawdot(x, y)
def simplify(expr):
    return _.simplify(expr)
def vpa(expr):
    return _.vpa(expr)
def readfile(path):
    return _.readfile(path)
def savefile(data,path):
    _.savefile(data,path)
def mtimes(a,b):
    return _.mtimes(a,b)
def mpower(a,b):
    return _.mpower(a,b)
def add(*a):
    return _.add(a)
def subtract(*a):
    return _.subtract(a)
def times(*a):
    return _.times(a)
def divide(*a):
    return _.divide(a)
def mod(*a):
    return _.mod(a)