my code:

#@title Interval intersection

def interval$\_$and$($self$,$ other$)$:

$"""$Intersection; returns an interval, or None."""

class Interval:

def $\_\_$init$\_\_($self$,$ x$0,$ x$1)$:

self.x$0=$ x$0$

self.x$1=$ x$1$

def $\_\_$and$\_\_($self$,$ other$)$:

$"""$Intersection; returns an interval, or None."""

# Check if 'other' is an instance of Interval

if not isinstance$($other$,$ Interval$)$:

return None

# Calculate intersection

intersection$\_$start $=$ max$($self$.$x$0,$ other.x$0)$

intersection$\_$end $=$ min$($self$.$x$1,$ other.x$1)$

# Check if there is a valid intersection

if intersection$\_$start $<=$ intersection$\_$end:

return Interval$($intersection$\_$start, intersection$\_$end$)$

else:

return None

# Tests

result$\_$interval $=$ Interval$(3,10)$ & Interval$(6,20)$

expected$\_$interval $=$ Interval$(6,10)$

assert result$\_$interval is not None

assert abs$($result$\_$interval.x$0-$ expected$\_$interval.x$0)<1$e$-10$

assert abs$($result$\_$interval.x$1-$ expected$\_$interval.x$1)<1$e$-10$

assert Interval$(3,4)$ & Interval$(5,6)$ is None

Interval.$\_\_$and$\_\_=$ interval$\_$and

does not work this code:

assert Interval$(3,10)$ & Interval$(6,20)==$ Interval$(6,10)$

assert Interval$(3,4)$ & Interval$(5,6)$ is None