diff --git a/ChangeLog b/ChangeLog
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 ChangeLog
 
+v0.3.0.4 2018/11/05
+	(2018/11/05) PS1 - fixed some optional compiler warnings.
+	(2018/11/05) PS1 - cabal: moved superdoc to setup-depends.
+	(2018/11/05) PS1 - disabled simplifiable-class-constraints
+	compiler warning.
+
 v0.3.0.3 2016/07/27
 	(2016/07/27) PS1 - relaxed package dependencies to accommodate
 	older versions of ghc and base.
diff --git a/Quantum/Synthesis/Clifford.hs b/Quantum/Synthesis/Clifford.hs
--- a/Quantum/Synthesis/Clifford.hs
+++ b/Quantum/Synthesis/Clifford.hs
@@ -296,6 +296,7 @@
 -- | 'tconj2' /a/ /b/ returns (/K/, /c/, /d/) such that
 -- 
 -- * /E/[sup /a/]/X/[sup /b/]/T/ = /K//T//X/[sup /b/]/S/[sup /c/]ω[sup /d/].
+tconj :: Int -> Int -> (Axis, Int, Int)
 tconj 0 0 = (Axis_I,  0, 0)
 tconj 0 1 = (Axis_I,  1, 7)
 tconj 1 0 = (Axis_H,  3, 3)
diff --git a/Quantum/Synthesis/Diophantine.hs b/Quantum/Synthesis/Diophantine.hs
--- a/Quantum/Synthesis/Diophantine.hs
+++ b/Quantum/Synthesis/Diophantine.hs
@@ -267,6 +267,7 @@
     -- prime divisor that occurs as an odd power and is congruent to 7
     -- mod n.
     return Nothing
+  | otherwise = error "dioph_int_assoc_prime"
   where
     n_mod_4 = n `mod` 4
     n_mod_8 = n `mod` 8
diff --git a/Quantum/Synthesis/GridSynth.hs b/Quantum/Synthesis/GridSynth.hs
--- a/Quantum/Synthesis/GridSynth.hs
+++ b/Quantum/Synthesis/GridSynth.hs
@@ -26,7 +26,6 @@
 
 import System.Random
 import Data.Function
-import Data.Number.FixedPrec
 
 -- ----------------------------------------------------------------------
 -- * Approximate synthesis
@@ -239,7 +238,9 @@
     err = sqrt (real (hs_sqnorm (uU_fixed - zrot_fixed)) / 2)
     uU_fixed = matrix_map fromDOmega uU
     zrot_fixed = zrot (theta :: r)
-    
+
+data Phase = Phase0 | Phase1
+
 -- | The internal implementation of the ellipse-based approximate
 -- synthesis algorithm, up to a phase. The parameters are the same as
 -- for 'gridsynth_internal'.
@@ -253,9 +254,9 @@
   opG = to_upright_sets region0 disk0
   raw_candidates0 = gridpoints2_increasing_with_gridop region0 disk0 opG
   raw_candidates1 = gridpoints2_increasing_with_gridop region1 disk1 opG
-  candidates0 = [ (t, 0, us) | (k, us) <- raw_candidates0,
+  candidates0 = [ (t, Phase0, us) | (k, us) <- raw_candidates0,
                                let t = tcount k ]
-  candidates1 = [ (t, 1, us') | (k, us) <- raw_candidates1,
+  candidates1 = [ (t, Phase1, us') | (k, us) <- raw_candidates1,
                                 let t = 1 + tcount k,
                                 let us' = [ u * delta_inv | u <- us ] ]
   merged = mergeBy (compare `on` first) candidates0 candidates1
@@ -278,7 +279,7 @@
       xi = real (1 - adj u * u)
       answer_t = run_bounded effort $ diophantine_dyadic g1 xi
   
-  with_successful_candidate u t 0 = (uU, log_err) where
+  with_successful_candidate u t Phase0 = (uU, log_err) where
     uU | denomexp (u + t) < denomexp (u + omega * t)
                = matrix2x2 (u, -(adj t)) (t, adj u)
        | otherwise
@@ -290,7 +291,7 @@
     uU_fixed = matrix_map fromDOmega uU
     zrot_fixed = zrot (theta :: r)
     
-  with_successful_candidate u t 1 = (uU, log_err) where
+  with_successful_candidate u t Phase1 = (uU, log_err) where
     uU | denomexp (u + t) < denomexp (u + omega * t)
                = matrix2x2 (u, -(adj t) * omega_inv) (t, adj u * omega_inv)
        | otherwise
diff --git a/Quantum/Synthesis/SymReal.hs b/Quantum/Synthesis/SymReal.hs
--- a/Quantum/Synthesis/SymReal.hs
+++ b/Quantum/Synthesis/SymReal.hs
@@ -11,7 +11,7 @@
 import Quantum.Synthesis.ArcTan2
 
 import Control.Monad
-import Data.Char (isAlpha, isAlphaNum, isDigit)
+import Data.Char (isDigit)
 import Data.Number.FixedPrec
 import Text.ParserCombinators.ReadP
 import Data.Ratio
diff --git a/newsynth.cabal b/newsynth.cabal
--- a/newsynth.cabal
+++ b/newsynth.cabal
@@ -7,7 +7,7 @@
 -- PVP summary:      +-+------- breaking API changes
 --                   | | +----- non-breaking API additions
 --                   | | | +--- code changes with no API change
-version:             0.3.0.3
+version:             0.3.0.4
 
 -- A short (one-line) description of the package.
 synopsis:            Exact and approximate synthesis of quantum circuits
@@ -60,7 +60,7 @@
 maintainer:          selinger@mathstat.dal.ca
 
 -- A copyright notice.
-copyright:           Copyright (c) 2012-2016 Neil J. Ross and Peter Selinger
+copyright:           Copyright (c) 2012-2018 Neil J. Ross and Peter Selinger
 
 -- A classification category for future use by the package catalogue
 -- Hackage. These categories have not yet been specified, but the
@@ -85,12 +85,14 @@
   -- other-modules:       
   
   -- Other library packages from which modules are imported.
-  build-depends:       base >= 4.5 && < 5, random >= 1.0, fixedprec >= 0.2.2, superdoc >= 0.1, containers >= 0.5
+  build-depends:       base >= 4.5 && < 5, random >= 1.0, fixedprec >= 0.2.2, containers >= 0.5
 
   -- Additional options for GHC when the package is built with
   -- profiling enabled.
   ghc-prof-options:
 
+  ghc-options:  -fno-warn-simplifiable-class-constraints
+  
 executable gridsynth
   -- .hs or .lhs file containing the Main module.
   main-is:             gridsynth.hs
@@ -102,4 +104,7 @@
   other-modules:       CommandLine
   
   -- Other library packages from which modules are imported.
-  build-depends:       base >= 4.5 && < 5, random >= 1.0, time >= 1.4, superdoc >= 0.1, newsynth
+  build-depends:       base >= 4.5 && < 5, random >= 1.0, time >= 1.4, newsynth
+
+custom-setup
+  setup-depends:       base >= 4.5, superdoc >= 0.1