anchor.diff:  
   /// Logical negation of the top stack element.
   class NegateInstruction extends InstructionTemplate {
  -  String get name => 'not';
  -
     const NegateInstruction();
   
     void execute(VM vm, _) => vm.pushStack(
         NumberType.uint8, vm.popStack(NumberType.uint8) == 0 ? 1 : 0);
  +
  +  String format(int _) => 'not';
   }
   
   /// Thrown when the execution of a program reaches the end of the `main`
  
positive.code: /// method.
  abstract class ArithmeticOperationInstruction extends InstructionTemplate {
    final NumberType numberType;
  
    const ArithmeticOperationInstruction(this.numberType);
  
  
negative.code: 
    Instruction(this.implementation, this.tokens, [this.immediateValue]);
  
    String toString() => implementation.format(argument);
  }
  
  /// Implements a machine instruction that can be executed by a [VM].
  