public override LazyNumber Eval(LazyNumber v1, LazyNumber v2)
{
return(new FunLazyNumberS(() => op.Invoke(v1.Eval(), v2.Eval())));
}
public override LazyNumber EvalUnary(LazyNumber v)
{
return(new FunLazyNumberS(() => this.op.Invoke(v.Eval())));
}