def add(x, y):
    """Adds x to y."""
    return x + y


def subtract(x, y):
    return y - x


def double(x):
    return add(x, x)


def square(x):
    return x * x


def displacement2(X, Y):
    return [subtract(Y[0], X[0]), subtract(Y[1], X[1])]

9061028f0449a5bad72584feca10694e5a693d6c
<mask token>


def double(x):
    return add(x, x)


<mask token>

def add(x, y):
    """Adds x to y."""
    return x + y


<mask token>


def double(x):
    return add(x, x)


<mask token>

def add(x, y):
    """Adds x to y."""
    return x + y


def subtract(x, y):
    return y - x


def double(x):
    return add(x, x)


<mask token>


def displacement2(X, Y):
    return [subtract(Y[0], X[0]), subtract(Y[1], X[1])]

def add(x, y):
    """Adds x to y."""
    return x + y


def subtract(x, y):
    return y - x


def double(x):
    return add(x, x)


def square(x):
    return x * x


def displacement2(X, Y):
    return [subtract(Y[0], X[0]), subtract(Y[1], X[1])]
