Created solutions for all five problems

solutions/pr1.cql

+.in
+A:2, # declare input files and their numbers of cols in .in section
+B:2
+
+.out # statements for the query are in .out section
+A x B; # returns the cartesian product of the two sets (conjunction)
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solutions/pr2.cql

+.in
+A:3
+
+.out
+filter((r) -> isSubstring(r[1], r[2]));
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solutions/pr3.cql

+.in
+A:3
+
+.out
+filter (\r -> r[2] == r[3]); # data the the function works on (e.g. input set this time) goes in [], extra info (e.g. predicate in this case) goes in ()
+map(\r -> r[3,1]); # can also be map[\_](\r ...), where \_ is output of last operation. 

solutions/pr4.cql

+.in
+P: 4,
+Q: 4
+
+.out
+P x Q;
+filter(\r -> r[4] == r[5]);
+let func f(x,y) = if (empty(x)) then y else x;
+map(\r -> [r[1], f(r[2], r[6]), f(r[3], r[7]), f(r[4], r[8]));
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solutions/pr5.cql

+.in
+A:1
+
+.out
+map[A](\r -> [r[1],"0",r[1]]);
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