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| heath@B570:~/Sandbox/Project-Euler-Problems/haskell$ ghc -o four four.hs
[1 of 1] Compiling Main ( four.hs, four.o )
four.hs:19:20:
No instance for (Num String)
arising from a use of `*'
Possible fix: add an instance declaration for (Num String)
In the expression: x * y
In the first argument of `maximum', namely
`[x * y |
x <- [100 .. 999],
pal x == True,
y <- [100 .. 999],
pal y == True]'
In the expression:
maximum
[x * y |
x <- [100 .. 999], pal x == True, y <- [100 .. 999], pal y == True]
four.hs:19:62:
No instance for (Enum String)
arising from the arithmetic sequence `100 .. 999'
Possible fix: add an instance declaration for (Enum String)
In the expression: [100 .. 999]
In a stmt of a list comprehension: y <- [100 .. 999]
In the first argument of `maximum', namely
`[x * y |
x <- [100 .. 999],
pal x == True,
y <- [100 .. 999],
pal y == True]'
|
