The general form of a return statement
is the word return, followed by an expression.
And the rules for executing a return statement
are, first, evaluate the expression, producing a memory address.
And second, pass back that memory address to the caller.
The general form of a function definition is the word def, followed by the name of
the function and then zero or more parameters separated by comas.
Next comes the body of the function, which is
one or more statements often ending with a return statement.
Notice that the body is indented.