The // operator is not truncation for negative numbers.

[VizIT]

In 04-Semantics-Operators.ipynb the // operator is described as
a // b | Floor division | Quotient of a and b, removing fractional parts
and
Floor division is true division with fractional parts truncated
Which works for the examples provided. However, in an active Jupyter notebook with negative numbers we see
-5/2 => -2.5
and
-5//2 => -3
This is what one would expect from floor division, but the text is a bit misleading in this case. From the text one would expect -2 here.