2 files changed, 21 insertions, 1 deletions

diff --git a/lib/Numeric/LinearAlgebra/Tests/Instances.hs b/lib/Numeric/LinearAlgebra/Tests/Instances.hs
index af486c8..e7fecf2 100644
--- a/lib/Numeric/LinearAlgebra/Tests/Instances.hs
+++ b/lib/Numeric/LinearAlgebra/Tests/Instances.hs
@@ -20,6 +20,7 @@ module Numeric.LinearAlgebra.Tests.Instances(
     WC(..),     rWC,cWC,
     SqWC(..),   rSqWC, cSqWC,
     PosDef(..), rPosDef, cPosDef,
+    Consistent(..), rConsist, cConsist,
     RM,CM, rM,cM
 ) where
 
@@ -116,6 +117,19 @@ instance (Field a, Arbitrary a) => Arbitrary (PosDef a) where
         return $ PosDef (0.5 .* p + 0.5 .* ctrans p)
     coarbitrary = undefined
 
+-- a pair of matrices that can be multiplied
+newtype (Consistent a) = Consistent (Matrix a, Matrix a) deriving Show
+instance (Field a, Arbitrary a) => Arbitrary (Consistent a) where
+    arbitrary = do
+        n <- chooseDim
+        k <- chooseDim
+        m <- chooseDim
+        la <- vector (n*k)
+        lb <- vector (k*m)
+        return $ Consistent ((n><k) la, (k><m) lb)
+    coarbitrary = undefined
+
+
 type RM = Matrix Double
 type CM = Matrix (Complex Double)
 
@@ -140,3 +154,5 @@ cSqWC (SqWC m) = m :: CM
 rPosDef (PosDef m) = m :: RM
 cPosDef (PosDef m) = m :: CM
 
+rConsist (Consistent (a,b)) = (a,b::RM)
+cConsist (Consistent (a,b)) = (a,b::CM)
diff --git a/lib/Numeric/LinearAlgebra/Tests/Properties.hs b/lib/Numeric/LinearAlgebra/Tests/Properties.hs
index 55e9a1b..5663b86 100644
--- a/lib/Numeric/LinearAlgebra/Tests/Properties.hs
+++ b/lib/Numeric/LinearAlgebra/Tests/Properties.hs
@@ -34,7 +34,8 @@ module Numeric.LinearAlgebra.Tests.Properties (
     hessProp,
     schurProp1, schurProp2,
     cholProp,
-    expmDiagProp
+    expmDiagProp,
+    multProp1, multProp2
 ) where
 
 import Numeric.LinearAlgebra
@@ -151,3 +152,6 @@ cholProp m = m |~| ctrans c <> c && upperTriang c
 expmDiagProp m = expm (logm m) :~ 7 ~: complex m
     where logm m = matFunc log m
 
+multProp1 (a,b) = a <> b |~| mulH a b
+
+multProp2 (a,b) = trans (a <> b) |~| trans b <> trans a