Doubt 1:

L1 should be subset of L2 for a,b,c and not for d

for 'd' L2 is a subset of L1

Doubt 2:

Anything with Kleen closer is regular

regular.CSL=CSL

L1 should be subset of L2 for a,b,c and not for d

for 'd' L2 is a subset of L1

Doubt 2:

Anything with Kleen closer is regular

regular.CSL=CSL