### 11.13.2 The abscissa of a point or vector in the plane: abscissa

See section 12.12.1 for abscissas in three-dimensional geometry.

The abscissa command takes a point as argument.

abscissa returns the abscissa (x-coordinate).
Input:

abscissa(point(1 + 2*i))

Output:

1

Input:

abscissa(point(i) - point(1 + 2*i))

Output:

-1

Input:

abscissa(1 + 2*i)

Output:

1

Input:

abscissa([1,2])

Output:

1