Hello, I have the following code from the Diagrams package tutorial:

{-# LANGUAGE NoMonomorphismRestriction #-}

import Diagrams.Prelude import Diagrams.Backend.SVG.CmdLine

main = mainWith (example :: Diagram B R2) example = circle 1 # fc blue # lw veryThick # lc purple # dashing [0.2,0.05] 0

I get the following error on compilation using GHC 7.6.3: ghc --make DiagramsTutorial-2.lhs [1 of 1] Compiling Main ( DiagramsTutorial-2.lhs, DiagramsTutorial-2.o ) DiagramsTutorial-2.lhs:10:33: Could not deduce (Fractional (Measure R2)) arising from the literal `0.2' from the context (TrailLike b, Transformable b, HasStyle b, V b ~ R2) bound by the inferred type of example :: (TrailLike b, Transformable b, HasStyle b, V b ~ R2) => b at DiagramsTutorial-2.lhs:(7,3)-(10,43) Possible fix: add an instance declaration for (Fractional (Measure R2)) In the expression: 0.2 In the first argument of `dashing', namely `[0.2, 0.05]' In the second argument of `(#)', namely `dashing [0.2, 0.05] 0' DiagramsTutorial-2.lhs:10:43: Could not deduce (Num (Measure R2)) arising from the literal `0' from the context (TrailLike b, Transformable b, HasStyle b, V b ~ R2) bound by the inferred type of example :: (TrailLike b, Transformable b, HasStyle b, V b ~ R2) => b at DiagramsTutorial-2.lhs:(7,3)-(10,43) Possible fix: add an instance declaration for (Num (Measure R2)) In the second argument of `dashing', namely `0' In the second argument of `(#)', namely `dashing [0.2, 0.05] 0' In the expression: circle 1 # fc blue # lw veryThick # lc purple # dashing [0.2, 0.05] 0 Thanks for any help. Roger