I've read lots of threads about "I've been to London'.
And I know that what the sentence means. But nonetheless, I am curious about the semantic meaning.
I've understood the sentence like that 'been' means fundamentally very much simillar to 'existed', and 'to' means, unlike 'toward(s)', that the sum of the both meanings 'direction' and 'arrived'. Based on the above information, I think 'been to' means that 'I existed at where I arrived after leaving home'. Therefore if 'have' added, I suppose 'have been to' would mean that 'I have a situation that I existed at where I arrived after leaving home' by regarding the verb 'have' as a verb kind of having an object. In this way I can understand why the sentence 'I've been to London' has the meaning of experience. But is it also possible way, despite unusual, to think that as I am still at London? because I can have the situation at London where I arrived after leaving home until now.
And people say the sentence implies 'has gone' and 'has come back.' But I think it could be so only if a context is of experience. But if a context not of it, I think the 'have been to' couldn't imply 'has come back', but only 'has gone'.