Yes, we have the similar select's too.
ex. Select min(mat_id) from matrix where 13=0 and
select min(mat_id) from matrix where 0=0.
From what I know they are used for cross field validations.
I don't knwo how tehy work. But assume that i want to make sure that the default rate column and assignment rate column has different values for same min(id).
then you will do 13=0 when they are equal it will be 0=0.
I don't know how it knows that I am comparing rates and why number 13=0 etc.
may be some one with better knowledge will be able to explain this.
Also, they have concerns that this makes the poor performance for big tables. But I have no idea.

thank
Sonali