================================================================================
Desugared:
f{-r3C,x-}  :: 
    _forall_
    [t{-aBt-} t{-aBF-} t{-aBI-} t{-aBS-}]
    =>
    [t{-aBt-}]
    -> (t{-aBF-}, t{-aBI-})
    -> PrelBase.Bool{-34,p-}
    -> [t{-aBS-}]
{-# L #-}
f{-r3C,x-} =
    _/\_ t{-aBt-} t{-aBF-} t{-aBI-} t{-aBS-} -> \ ds_dGi  :: 
						      [t{-aBt-}]
						  {-# L #-}
						  ds_dGi y_r3e  :: 
							     (t{-aBF-}, t{-aBI-})
							 {-# L #-}
							 y_r3e ds_dGj  :: 
								   PrelBase.Bool{-34,p-}
							       {-# L #-}
							       ds_dGj ->
	let {
	  fail_dGE  :: 
	      [t{-aBS-}]
	  {-# L #-}
	  fail_dGE =
	      case y_r3e of { PrelTup.(,){-62,p-}{i} y_r3k ys_r3l  ->
	      let {
		z_r3n  :: 
		    PrelBase.Bool{-34,p-}
		{-# L #-}
		z_r3n =
		    ds_dGj } in
	      let {
		a_r3j  :: 
		    (t{-aBF-}, t{-aBI-})
		{-# L #-}
		a_r3j =
		    y_r3e } in
	      let {
		x_r3h  :: 
		    [t{-aBt-}]
		{-# L #-}
		x_r3h =
		    ds_dGi
	      } in 
		PrelBase.[]{-5i,p-}{i}
		    _@_ t{-aBS-};}
	} in 
	  case ds_dGi of {
	    PrelBase.:{-55,p-}{i} ds_dGM ds_dGL ->
		fail_dGE;
	    PrelBase.[]{-5i,p-}{i} ->
		case ds_dGj of {
		  PrelBase.False{-58,p-}{i} ->
		      fail_dGE;
		  PrelBase.True{-5E,p-}{i} ->
		      PrelBase.[]{-5i,p-}{i}
			  _@_ t{-aBS-};
		};
	  }