             selector:#selector(notifiedKeyboardChanged(sender:)),
             name:NSNotification.Name.UIKeyboardWillChangeFrame,
             object:nil)
+        
+        guard
+        
+            let polynomial:DPolynomial = self.controller.polynomial
+        
+        else
+        {
+            return
+        }
+        
+        if polynomial.showAsDivision
+        {
+            asDivision()
+        }
+        else
+        {
+            asDecimal()
+        }
     }
     
     required init?(coder:NSCoder)

        
        let blur:VBlur = VBlur.light()
        
        let viewText:VLinearEquationsPolynomialText = VLinearEquationsPolynomialText(
            controller:self.controller)
        self.viewText = viewText
        
        let viewControl:VLinearEquationsPolynomialControl = VLinearEquationsPolynomialControl(
            controller:self.controller)
        self.viewControl = viewControl

            
            let polynomial:DPolynomial = controller.polynomial
            
        else
        {
            return
        }
        
        let dividend:Double = polynomial.coefficientDividend
        let divisor:Double = polynomial.coefficientDivisor
        
        if polynomial.showAsDivision
        {
            let dividendNumber:NSNumber = NSNumber(value:dividend)
            let divisorNumber:NSNumber = NSNumber(value:divisor)
            
            guard
            
                let viewDivision:VLinearEquationsPolynomialDivision = self.viewDivision,
                let dividendString:String = numberFormatter.string(
                    from:dividendNumber),
                let divisorString:String = numberFormatter.string(
                    from:divisorNumber)
            
            else
            {
                return
            }
            
            let curatedDividend:String = curatedNumber(number:dividendString)
            let curatedDivisor:String = curatedNumber(number:divisorString)
            
            viewDivision.fieldDividend.text = curatedDividend
            viewDivision.fieldDivisor.text = curatedDivisor
            viewDivision.fieldDividend.becomeFirstResponder()
        }
        else
        {
            let coefficient:Double = dividend / divisor
            let coefficentNumber:NSNumber = NSNumber(value:coefficient)
            
            guard
                
                let viewText:VLinearEquationsPolynomialText = self.viewText,
                let coefficientString:String = numberFormatter.string(
                    from:coefficentNumber)
                
            else
            {
                return
            }
            
            let curatedCoefficient:String = curatedNumber(number:coefficientString)
            viewText.text = curatedCoefficient
            viewText.becomeFirstResponder()
        }
    }
    
    //MARK: public
    
    func startEdition()
    {   
        readPolynomial()
        viewIndeterminate.refresh()
    }
    
    func endEdition()
    {
        viewText?.isHidden = true
        viewDivision?.isHidden = true
    }
    
    //MARK: textView delegate
