Why is it computationally expensive to check whether the destination of an assigned goto is in its list of statement labels?

this would start to sound a little like mortal combat

only #2 represents an object at rest on a table.

in #1, there is no normal force due to the table; the object is accelerating downward.

in #3, the vertical forces are not balanced; the object is accelerating downward.

in #4, neither the vertical nor the horizontal forces are balanced. the object is accelerating upwards and to the right.