Îõ³h$ýu     SafeÙQdecClass of decidable types.Lawa# should be a Proposition, i.e. the  answers should be unique.Note:& We'd want to have decidable equality :~:= here too, but that seems to be a deep dive into singletons.decDecidable (nullary) relations.decIntuitionistic negation.decWe can negate anything twice.*Double-negation elimination is inverse of  and generally impossible.dec/Triple negation can be reduced to a single one.decWeak contradiction. decA variant of contraposition. decFlip  branches. decShow .decShow $ Yes ()"Yes ()"decShow $ No id "No " decConvert  a to  a, forgetting the  evidence. decConvert  to , forgetting the evidence.dec, it's .dec, it's .dec  respects this ordering.Note: yet if you have p :: a and p ::  a, something is wrong.decThis relies on the fact that a is  proposition in h-Prop sense.dec0Products of decidable propositions are decidabledec is falsehood.dec() is truth.        !"#$ dec-0.0.5-LSJGH7sanwfJqZdvBnYe8h Data.Type.Dec DecidabledecideDecYesNoNegtoNegNeg tripleNeg contradictcontrapositiondecNegdecShow decToMaybe decToBool boringYesabsurdNo$fOrdDec$fEqDec $fBoringDec$fDecidable(,)$fDecidableVoid $fDecidable()base GHC.MaybeMaybeghc-prim GHC.TypesBool!boring-0.2-DaIcLpIEXDhFnk9pCeVM7j Data.Boringboringabsurd Data.VoidVoid