Desugared:
Test.a :: for all d, e, f, g. ([d], [e], [f]) -> [g]
Test.a = /\ t118 t119 t120 t121 -> \ ds.314 -> Nil! t121
Test.b :: for all d, e. [d] -> [e]
Test.b =
    /\ t134 t135 -> \ ds.323 ->
	let
	  x.328 =
	      case ds.323 of {
		(:) x.324 ds.325 ->
		    case ds.325 of {
		      (:) xs.326 ys.327 -> x.324
		      _ -> 
			  (error Char)
			      "``impossible'' pattern-matching error!\n"S
		    }
		_ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	      } in
	let
	  xs.333 =
	      case ds.323 of {
		(:) x.329 ds.330 ->
		    case ds.330 of {
		      (:) xs.331 ys.332 -> xs.331
		      _ -> 
			  (error Char)
			      "``impossible'' pattern-matching error!\n"S
		    }
		_ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	      } in
	let
	  ys.338 =
	      case ds.323 of {
		(:) x.334 ds.335 ->
		    case ds.335 of {
		      (:) xs.336 ys.337 -> ys.337
		      _ -> 
			  (error Char)
			      "``impossible'' pattern-matching error!\n"S
		    }
		_ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	      }
	in  Nil! t135
Test.c :: for all d, e, f, g. <Fractional f> -> <Num e> -> g -> d -> e -> f -> g
Test.c =
    /\ o139 t140 t143 o138 -> \ dict.144 dict.141 ->
	let
	  dict.145 = (sdsel.Num.Eq t143) ((sdsel.Fractional.Num t143) dict.144) in
	let dict.142 = (sdsel.Num.Eq t140) dict.141 in
	let c.137 = \ x.87 ds.339 ds.340 ds.341 -> let x.87 = x.87 in  x.87
	in  c.137
Test.d :: for all d, e. <Num e> -> <Ord d> -> <Num d> -> d -> e
Test.d =
    /\ t171 t174 -> \ dict.175 dict.173 dict.172 ->
	let dict.169 = dict.175 in
	let dict.163 = dict.169 in
	let dict.157 = dict.163 in
	let dict.152 = dict.157 in
	let dict.166 = dict.172 in
	let dict.160 = dict.166 in
	let dict.154 = dict.160 in
	let dict.149 = dict.154 in
	let dict.167 = dict.173 in
	let dict.161 = dict.167 in
	let dict.155 = (sdsel.Ord.Eq t171) dict.161 in
	let dict.150 = dict.155 in
	let
	  d.147 =
	      \ ds.344 ->
		  let
		    fail.345 =
			(error t174)
			    "\"ds020.hs\", line 17: pattern-matching failure [function binding]\n"S in
		  let
		    fail.349 =
			let
			  n.88 =
			      let
				n.346 =
				    (fromInteger t171) dict.160 (MkInteger! 4##)
			      in 
				case
				    ((>= t171)
					 dict.161
					 ds.344
					 ((fromInteger t171)
					      dict.160 (MkInteger! 4##)))
				of {
				  True ->
				      let
					n.88 =
					    (- t171)
						dict.160
						ds.344
						((fromInteger t171)
						     dict.160 (MkInteger! 4##))
				      in  n.88
				  False ->
				      (error Char)
					  "``impossible'' pattern-matching error!\n"S
				}
			in  (fromInteger t174) dict.163 (MkInteger! 2##)
		  in 
		    case
			((== t171)
			     dict.150
			     ((fromInteger t171) dict.149 (MkInteger! 11##))
			     ds.344)
		    of {
		      True -> (fromInteger t174) dict.152 (MkInteger! 4##)
		      False ->
			  case
			      ((== t171)
				   dict.155
				   ((fromInteger t171)
					dict.154 (MkInteger! 12##))
				   ds.344)
			  of {
			    True -> (fromInteger t174) dict.157 (MkInteger! 3##)
			    False -> fail.349
			  }
		    }
	in  d.147
Test.f :: for all d, e. [d] -> [e]
Test.f =
    /\ t182 t183 -> \ x.352 ->
	let
	  x.353 =
	      case x.352 of {
		Nil -> x.352
		_ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	      }
	in  Nil! t183
Test.g :: for all d, e. [d] -> [e]
Test.g = /\ t186 t187 -> \ ds.356 -> Nil! t187
ds.357 :: ([t191], [t192], [t193])
ds.357 = MkTuple3! [t191] [t192] [t193] (Nil! t191) (Nil! t192) (Nil! t193)
ds.358 :: ([t197], [t198], [t199])
ds.358 = MkTuple3! [t197] [t198] [t199] (Nil! t197) (Nil! t198) (Nil! t199)
ds.359 :: [t208]
ds.359 = /\ t208 -> Nil! t208
Test.x1 :: for all d. d
Test.x1 =
    /\ t208 ->
	case ds.359 of {
	  (:) x1.363 ds.364 ->
	      case ds.364 of {
		(:) xs1.365 ys1.366 -> x1.363
		_ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	      }
	  _ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	}
Test.xs1 :: for all d. d
Test.xs1 =
    /\ t208 ->
	case ds.359 of {
	  (:) x1.367 ds.368 ->
	      case ds.368 of {
		(:) xs1.369 ys1.370 -> xs1.369
		_ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	      }
	  _ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	}
Test.ys1 :: for all d. [d]
Test.ys1 =
    /\ t208 ->
	case ds.359 of {
	  (:) x1.371 ds.372 ->
	      case ds.372 of {
		(:) xs1.373 ys1.374 -> ys1.374
		_ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	      }
	  _ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	}
ds.375 :: [t217]
ds.375 = /\ t217 -> Nil! t217
Test.x :: for all d. d
Test.x =
    /\ t217 ->
	case ds.375 of {
	  (:) x.379 ds.380 ->
	      case ds.380 of {
		(:) xs.381 ys.382 ->
		    let ys.383 = ys.382 in
		    let xs.384 = xs.381 in let x.385 = x.379 in  x.385
		_ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	      }
	  _ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	}
Test.xs :: for all d. d
Test.xs =
    /\ t217 ->
	case ds.375 of {
	  (:) x.386 ds.387 ->
	      case ds.387 of {
		(:) xs.388 ys.389 ->
		    let ys.390 = ys.389 in
		    let xs.391 = xs.388 in let x.392 = x.386 in  xs.391
		_ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	      }
	  _ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	}
Test.ys :: for all d. [d]
Test.ys =
    /\ t217 ->
	case ds.375 of {
	  (:) x.393 ds.394 ->
	      case ds.394 of {
		(:) xs.395 ys.396 ->
		    let ys.397 = ys.396 in
		    let xs.398 = xs.395 in let x.399 = x.393 in  ys.397
		_ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	      }
	  _ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	}
{- plain CoRec -}
ds.406 :: [t254]
ds.406 =
    /\ t254 ->
	let dict.410 = dfun.Eq.Int in
	let
	  eq2.413 =
	      eqInt
		  (let dict.411 = dfun.Num.Int in  MkInt! 2#)
		  (let dict.412 = dfun.Num.Int in  MkInt! 4#) in
	let dict.414 = dfun.Eq.Int in
	let
	  eq3.417 =
	      eqInt
		  (let dict.415 = dfun.Num.Int in  MkInt! 3#)
		  (let dict.416 = dfun.Num.Int in  MkInt! 3#) in
	let dict.418 = dfun.Eq.Int in
	let
	  eq4.421 =
	      eqInt
		  (let dict.419 = dfun.Num.Int in  MkInt! 4#)
		  (let dict.420 = dfun.Num.Int in  MkInt! 2#)
	in 
	  case eq2.413 of {
	    True -> Nil! t254
	    False ->
		case eq3.417 of {
		  True -> :! t254 (Test.x2 t254) (Nil! t254)
		  False ->
		      case eq4.421 of {
			True -> :! t254 (Test.x2 t254) (Nil! t254)
			False -> Nil! t254
		      }
		}
	  }
Test.x2 :: for all d. d
Test.x2 =
    /\ t254 ->
	case ds.406 of {
	  (:) x2.422 ds.423 ->
	      case ds.423 of {
		(:) xs2.424 ys2.425 -> x2.422
		_ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	      }
	  _ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	}
Test.xs2 :: for all d. d
Test.xs2 =
    /\ t254 ->
	case ds.406 of {
	  (:) x2.426 ds.427 ->
	      case ds.427 of {
		(:) xs2.428 ys2.429 -> xs2.428
		_ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	      }
	  _ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	}
Test.ys2 :: for all d. [d]
Test.ys2 =
    /\ t254 ->
	case ds.406 of {
	  (:) x2.430 ds.431 ->
	      case ds.431 of {
		(:) xs2.432 ys2.433 -> ys2.433
		_ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	      }
	  _ ->  (error Char) "``impossible'' pattern-matching error!\n"S
	}
{- end plain CoRec -}
ds.435 :: for all d, e. <Num e> -> <Ord d> -> <Num d> -> (d, e)
ds.435 =
    /\ t273 t275 -> \ dict.276 dict.269 dict.274 ->
	let dict.267 = dict.276 in
	let dict.271 = dict.274 in
	let dict.265 = dict.271 in
	let dict.262 = dict.265 in
	let dict.260 = dict.269
	in 
	  let
	    {- CoRec -}
	    ds.434 =
		case
		    ((> t273)
			 dict.260
			 x3.257
			 ((fromInteger t273) dict.262 (MkInteger! 3##)))
		of {
		  True ->
		      MkTuple2!
			  t273
			  t275
			  ((fromInteger t273) dict.265 (MkInteger! 4##))
			  ((fromInteger t275) dict.267 (MkInteger! 5##))
		  False ->
		      case
			  ((<= t273)
			       dict.269
			       x3.257
			       ((fromInteger t273) dict.271 (MkInteger! 3##)))
		      of {
			True ->
			    MkTuple2!
				t273
				t275
				((fromInteger t273) dict.274 (MkInteger! 2##))
				((fromInteger t275) dict.276 (MkInteger! 3##))
			False ->
			    (error (t273, t275))
				"\"ds020.hs\", line 42: pattern-matching failure [pat binding]\n"S
		      }
		}
	    x3.257 =
		case ds.434 of {
		  MkTuple2 x3.257 y3.258 -> x3.257
		}
	    y3.258 =
		case ds.434 of {
		  MkTuple2 x3.257 y3.258 -> y3.258
		}
	    {- end CoRec -}
	  in  MkTuple2! t273 t275 x3.257 y3.258
Test.x3 :: for all d, e. <Num e> -> <Ord d> -> <Num d> -> d
Test.x3 =
    /\ t273 t275 -> \ dict.276 dict.269 dict.274 ->
	case (((ds.435 t273) t275) dict.276 dict.269 dict.274) of {
	  MkTuple2 x3.257 y3.258 -> x3.257
	}
Test.y3 :: for all d, e. <Num e> -> <Ord d> -> <Num d> -> e
Test.y3 =
    /\ t273 t275 -> \ dict.276 dict.269 dict.274 ->
	case (((ds.435 t273) t275) dict.276 dict.269 dict.274) of {
	  MkTuple2 x3.257 y3.258 -> y3.258
	}
ds.442 :: (Char, (Char, (Char, Char)))
ds.442 =
    let dict.451 = dfun.Eq.Int in
    let
      eq2.454 =
	  eqInt
	      (let dict.452 = dfun.Num.Int in  MkInt! 2#)
	      (let dict.453 = dfun.Num.Int in  MkInt! 4#) in
    let dict.455 = dfun.Eq.Int in
    let
      eq3.458 =
	  eqInt
	      (let dict.456 = dfun.Num.Int in  MkInt! 3#)
	      (let dict.457 = dfun.Num.Int in  MkInt! 3#) in
    let dict.459 = dfun.Eq.Int in
    let
      eq4.462 =
	  eqInt
	      (let dict.460 = dfun.Num.Int in  MkInt! 4#)
	      (let dict.461 = dfun.Num.Int in  MkInt! 2#)
    in 
      case eq2.454 of {
	True ->
	    MkTuple2!
		Char
		(Char, (Char, Char))
		(MkChar! 'a'#)
		(MkTuple2!
		     Char
		     (Char, Char)
		     (MkChar! 'a'#)
		     (MkTuple2! Char Char (MkChar! 'a'#) (MkChar! 'a'#)))
	False ->
	    case eq3.458 of {
	      True ->
		  MkTuple2!
		      Char
		      (Char, (Char, Char))
		      (MkChar! 'b'#)
		      (MkTuple2!
			   Char
			   (Char, Char)
			   (MkChar! 'b'#)
			   (MkTuple2! Char Char (MkChar! 'b'#) (MkChar! 'b'#)))
	      False ->
		  case eq4.462 of {
		    True ->
			MkTuple2!
			    Char
			    (Char, (Char, Char))
			    (MkChar! 'c'#)
			    (MkTuple2!
				 Char
				 (Char, Char)
				 (MkChar! 'c'#)
				 (MkTuple2!
				      Char Char (MkChar! 'c'#) (MkChar! 'c'#)))
		    False ->
			MkTuple2!
			    Char
			    (Char, (Char, Char))
			    (MkChar! 'd'#)
			    (MkTuple2!
				 Char
				 (Char, Char)
				 (MkChar! 'd'#)
				 (MkTuple2!
				      Char Char (MkChar! 'd'#) (MkChar! 'd'#)))
		  }
	    }
      }
Test.x4 :: Char
Test.x4 =
    case ds.442 of {
      MkTuple2 x4.463 ds.464 ->
	  case ds.464 of {
	    MkTuple2 y4.465 ds.466 ->
		case ds.466 of {
		  MkTuple2 z4.467 a4.468 -> x4.463
		}
	  }
    }
Test.y4 :: Char
Test.y4 =
    case ds.442 of {
      MkTuple2 x4.469 ds.470 ->
	  case ds.470 of {
	    MkTuple2 y4.471 ds.472 ->
		case ds.472 of {
		  MkTuple2 z4.473 a4.474 -> y4.471
		}
	  }
    }
Test.z4 :: Char
Test.z4 =
    case ds.442 of {
      MkTuple2 x4.475 ds.476 ->
	  case ds.476 of {
	    MkTuple2 y4.477 ds.478 ->
		case ds.478 of {
		  MkTuple2 z4.479 a4.480 -> z4.479
		}
	  }
    }
Test.a4 :: Char
Test.a4 =
    case ds.442 of {
      MkTuple2 x4.481 ds.482 ->
	  case ds.482 of {
	    MkTuple2 y4.483 ds.484 ->
		case ds.484 of {
		  MkTuple2 z4.485 a4.486 -> a4.486
		}
	  }
    }