mod180.hs:8:5: Couldn't match expected type ‘T’ with actual type ‘main:Mod180_A.T’ NB: ‘T’ is defined at Mod180_B.hs:3:1-10 ‘main:Mod180_A.T’ is defined at Mod180_A.hs:3:1-10 In the expression: x In an equation for ‘z’: z = x