diff options
Diffstat (limited to 'src/algebra/boolean.spad.pamphlet')
| -rw-r--r-- | src/algebra/boolean.spad.pamphlet | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/src/algebra/boolean.spad.pamphlet b/src/algebra/boolean.spad.pamphlet index 735c7fcf..d685c2cf 100644 --- a/src/algebra/boolean.spad.pamphlet +++ b/src/algebra/boolean.spad.pamphlet @@ -511,12 +511,15 @@ Bits(): Exports == Implementation where ++ This domain implements Kleene's 3-valued propositional logic. KleeneTrivalentLogic(): Public == Private where Public == PropositionalLogic with - false: % - unknown: % - true: % + false: % ++ the definite falsehood value + unknown: % ++ the indefinite `unknown' + true: % ++ the definite truth value _case: (%,[| false |]) -> Boolean + ++ x case false holds if the value of `x' is `false' _case: (%,[| unknown |]) -> Boolean + ++ x case unknown holds if the value of `x' is `unknown' _case: (%,[| true |]) -> Boolean + ++ s case true holds if the value of `x' is `true'. Private == add Rep == Byte -- We need only 3 bits, in fact. false == per(0::NonNegativeInteger::Byte) |