Fix comparable of PartialOrd (a,b) instance

Author: phadej

CHANGELOG.md

@@ -1,3 +1,7 @@
+# 2.1 (2022-12-27)
+
+- Fix `comprable` for `PartialOrd (a,b)` instance
+
 # 2.0.3 (2021-10-30)
 
 - Add instances for `Solo`

lattices.cabal

@@ -1,7 +1,6 @@
 cabal-version:      1.18
 name:               lattices
-version:            2.0.3
-x-revision:         4
+version:            2.1
 category:           Math
 license:            BSD3
 license-file:       LICENSE

src/Algebra/PartialOrd.hs

@@ -148,8 +148,6 @@ instance (PartialOrd a, PartialOrd b) => PartialOrd (a, b) where
     -- ordering is incompatible with the transitivity axiom we require for the derived partial order
     (x1, y1) `leq` (x2, y2) = x1 `leq` x2 && y1 `leq` y2
 
-    comparable (x1, y1) (x2, y2) = comparable x1 x2 && comparable y1 y2
-
 -- | @since 2.0.1
 instance (PartialOrd a, PartialOrd b) => PartialOrd (Either a b) where
     Left x  `leq` Left y  = leq x y

test/Tests.hs

@@ -95,6 +95,8 @@ tests = testGroup "Tests"
 
     , allLatticeLaws LNotLattice                         (Proxy :: Proxy String)
 
+    , allLatticeLaws (LBounded Partial Modular)          (Proxy :: Proxy (M2, M2))
+
     , allLatticeLaws (LHeyting Total   IsBoolean)        (Proxy :: Proxy All)
     , allLatticeLaws (LHeyting Total   IsBoolean)        (Proxy :: Proxy Any)
     , allLatticeLaws (LHeyting Partial IsBoolean)        (Proxy :: Proxy (Endo Bool)) -- note: it's partial!