# 99 questions/Solutions/47

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(*) Truth tables for logical expressions (2).

Continue problem P46 by defining and/2, or/2, etc as being operators. This allows to write the logical expression in the more natural way, as in the example: A and (A or not B). Define operator precedence as usual; i.e. as in Java.

```
-- functions as in solution 46
infixl 4 `or'`
infixl 6 `and'`
-- "not" has fixity 9 by default
```

Java operator precedence (descending) as far as I could fathom it:

logical not equality and xor or

Using "not" as a non-operator is a little evil, but then again these problems were designed for languages other than haskell :)