public RuleSpec Simplify(ISet <Mode> modesEntered, LexerSpec lexer)
{
var reducedModes = new HashSet <Mode>(Modes.Intersect(modesEntered));
var simplfiedExpression = Expression.Simplify(lexer);
if (reducedModes.Count >= Modes.Count && Expression == simplfiedExpression)
{
return(this);
}
return(new RuleSpec(reducedModes, Name, simplfiedExpression, Commands));
}