Hi Wolffy,

Thought I'd close the loop on this. I'm still going to keep messing with the combinations to try to exclude all non-mutually exclusive combinations, but there were some inherent problems with the logic once I started trying to tie in the actual meat and potatoes of what I was trying to do. I used sort of a loosely related approach to what we talked about and also implemented one of your initial bits of advice which was to set up a case expression in a view.
Instead of a case expression, I actually defined all possible combinations that I would want in a CTE and then reference that in my main query. So far it's working great! Here's what the CTE looks like:

;WITH

EXC_VIEW (ID, V, N)
AS (SELECT * FROM (

SELECT 100 AS ID, 3 AS V, 6 AS N
UNION ALL
SELECT 101 AS ID, 3 AS V, 11 AS N
UNION ALL
SELECT 102 AS ID, 3 AS V, 16 AS N
UNION ALL
SELECT 103 AS ID, 3 AS V, 21 AS N
UNION ALL
SELECT 104 AS ID, 3 AS V, 24 AS N
UNION ALL
SELECT 105 AS ID, 3 AS V, 27 AS N
UNION ALL
SELECT 106 AS ID, 7 AS V, 6 AS N
UNION ALL
SELECT 107 AS ID, 7 AS V, 9 AS N
UNION ALL
SELECT 108 AS ID, 7 AS V, 13 AS N
UNION ALL
SELECT 109 AS ID, 7 AS V, 16 AS N
UNION ALL
SELECT 110 AS ID, 7 AS V, 21 AS N
UNION ALL
SELECT 111 AS ID, 7 AS V, 25 AS N
UNION ALL
SELECT 112 AS ID, 8 AS V, 6 AS N
UNION ALL
SELECT 113 AS ID, 8 AS V, 13 AS N
UNION ALL
SELECT 114 AS ID, 8 AS V, 16 AS N
UNION ALL
SELECT 115 AS ID, 8 AS V, 22 AS N
UNION ALL
SELECT 116 AS ID, 8 AS V, 23 AS N
UNION ALL
SELECT 117 AS ID, 8 AS V, 25 AS N
UNION ALL
SELECT 118 AS ID, 18 AS V, 9 AS N
UNION ALL
SELECT 119 AS ID, 18 AS V, 11 AS N
UNION ALL
SELECT 120 AS ID, 18 AS V, 13 AS N
UNION ALL
SELECT 121 AS ID, 18 AS V, 19 AS N
UNION ALL
SELECT 122 AS ID, 18 AS V, 21 AS N
UNION ALL
SELECT 123 AS ID, 26 AS V, 6 AS N
UNION ALL
SELECT 124 AS ID, 26 AS V, 11 AS N
UNION ALL
SELECT 125 AS ID, 26 AS V, 16 AS N
UNION ALL
SELECT 126 AS ID, 26 AS V, 20 AS N
UNION ALL
SELECT 127 AS ID, 26 AS V, 23 AS N
UNION ALL
SELECT 128 AS ID, 26 AS V, 24 AS N
UNION ALL
SELECT 129 AS ID, 26 AS V, 27 AS N
UNION ALL
SELECT 130 AS ID, 26 AS V, 29 AS N
) V)

SELECT * FROM EXC_VIEW

I can then join the "scheduling" table that houses all the "visible" exccombos to the exc_view.v and join the "trips"table that houses all the "not visible" exccombos to exc_view.n...then when I select a Visible exccombo, then I only return the invisible that could correspond.

This takes some maintenance as combinations may be added later, but I still think this is a thousand times better than what we were doing than before.

Thanks again! You've really helped alot...I've gotten my old Algebra text books out so I can brush up on set theory, combinations and permutations