anchor.diff:          | None ->    error (FunctionExpected(denv, ty, mFunExpr))
   
   let ReportImplicitlyIgnoredBoolExpression denv m ty expr =
  -    let checkExpr m exprOpt =
  -        match exprOpt with 
  +    let checkExpr m expr =
  +        match expr with 
           | Expr.App(Expr.Val(vf, _, _), _, _, exprs, _) when vf.LogicalName = opNameEquals ->
               match exprs with 
               | Expr.App(Expr.Val(propRef, _, _), _, _, Expr.Val(vf, _, _) :: _, _) :: _ ->
  
positive.code:                 else TcExprThatCantBeCtorBody cenv overallExprTy envinner tpenv rhsExpr)
  
          if bkind = StandaloneExpression && not cenv.isScript then 
              UnifyUnitType cenv env.DisplayEnv mBinding overallPatTy (Some rhsExprChecked) |> ignore<bool>
  
          // Fix up the r.h.s. expression for 'fixed'
          let rhsExprChecked =
  
negative.code: and TcStmt cenv env tpenv synExpr =
      let expr, ty, tpenv = TcExprOfUnknownType cenv env tpenv synExpr
      let m = synExpr.Range
      let wasUnit = UnifyUnitType cenv env.DisplayEnv m ty expr
      if wasUnit then
          expr, tpenv
      else
  