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ASD Load Combinations

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Based on commentary in ASCE 7-95, the 1/3 allowable stress increase on 
combined stress, or its equivalent the 0.75 load factor, is allowed only when 
two or more "transient" loads are contained within the load combination. 
[This of course is counter to long past practice, as reflected for one in the 
AISC Spec (see ASD 9th, A5.2) , but it appears to be the re-think today]. 
Equations (12-7) through (12-11) are consistent with this new thinking, 
except it appears for (12-8) since there is a low probabiliity that L and Lr 
or S would occur at the same time (but not as low of a probability of L and W 
or E occuring at the same time -- say OK). 

Equations (12-12) through (12-16) are also consistent with the new criteria 
if one interprets the INTENT of the equations as written this way: In (12-13) 
for example, D + L + (W + E/1.4), the L cannot be taken as zero such that D + 
(W +E/1.4) results to which a 1/3 stress increase is applied. In other words, 
in all the equations for the 1/3 increase to apply, ALL individual loads must 
be included, and none excluded. This is the interpretation I have to make for 
this to be consistent and make sense. However,  suppose you do not have a 
"L", which can occur for non-building structures such as vessels/ tanks, or 
"L" happens to be very small for some reason. Looks like there is no load 
combination in the (12-12) through (12-16) group that covers this situation 
because there is no D + (W or E/1.4) combination similar to (12-9). So, you 
are stuck with (12-13) which becomes in effect D + (W or E/1.4) to which 
allowable stresses are increased by 1/3. To me this appears to be 
inconsistent and an oversight.