3 Duplicate or overlapping instance declarations
4 for `A B' defined at tcfail023.hs:13 and defined at tcfail023.hs:10
7 Couldn't match `B' against `Bool'
10 In the right-hand side of an equation for `op': True
13 Couldn't match `B' against `Bool'
16 In the right-hand side of an equation for `op': True
18 Compilation had errors