This file contains the structure used for testing the boolean
operators.   It should cover the routine exp_boolean. 

SCAFFOLDING CODE (some in scaffold.c, most in and.c)

This is the code that is common to all the binary operators; mainly
concerned with handling of children.

Nesting level
1
2
> 2


Test all conditions of children:

Left child 
	requires a temporary.
	Does not require a temporary.

	has tests
	does not have tests.

	has a setter which is the original expression (same nodes).
	has a setter which is a new tree (constructed from original)

	Positioning of child's setter:
		Before the tests.
			Because child uses tempvar.
			Because self uses tempvar.
		After the tests.
			Because child uses tempvar, but it's a reference.
			Because child doesn't use tempvar.

Ditto for right child.

Self has tests
	Yes.
	No.
	



INDIVIDUAL CODE:
	For every probe:

Case where flag is not set.
Case where flag is set.

In cases where multiple instrumentation types are possible, implement
above tests for only one type active and for all types active.  
Also determine that no instrumentation is added when all
instrumentation is turned off.
