Another foreign trip looms this week � to central Europe , just for 24 hours � one of those bits that shifted country in the middle of 20C. Flying Ryanair via Stanstead � I will stay at Mike�s which is quite nearby tomorrow night. I have invested in a warm coat a conventional black hat with a brim. I imagine I look Central European dressed like that but I don�t suppose that�s how I�ll look to the natives.

We sent in some 50 paras of our wit and wisdom to the Commons Select Committee on Skills yesterday � the deadline was tight but we seem to have got away with it � and it provides me with something to send round.

Next week is also looking busy by my standards. I am going to the University at Hatfield on Monday, picking Francis up at Reading at 9.30am. On Wednesday I am going to Warrington with Mike to talk about Poland and then back for a dinner discussion in central Birmingham. There is a related Birmingham University seminar on Thursday and I am meeting someone from there on Friday who�ll probably be at the seminar the day before.

I said to Stephen over the weekend that I think between him, Phil and myself we have got a grip of the national statistics in a way which others mostly don�t have. At the end of last week I did some work on the capital side of the national income accounts. We all use the expression GDP and we know that the G is gross. If there�s gross then there must be a net equivalent and to get from gross to net you have to get a handle on capital consumption. Capital stock can , it seems, be measured in two ways � at replacement cost or at a cost which reflects that some of the stuff is wearing out. And on top of the two meaurements there are two ways of expressing the value � two kinds of money. I think I have found my way through this and have calculated a time series for return on capital for about 9 years. I wrote one of the academics today explaining what I had done so that he could give me some words of warning or advice

Last week was slow for obvious reasons and I tried to get myself started with two things � the first was the trio music of Jimmy Giuffre from the very early 60s and the second was the grand theory of R Collins. RC seems to be a fan of the outfit where I briefly ended up in 1975 before launching into 25 years serving the Queen.

The bits of his grand narrative that really interested me were the German Universities � partly because I am visiting something that used to be one on Friday. (James says its rude to bring up the fact if they don�t.) There is a point where some ideas and values from these Us pass across at get lodged mostly at Trinity Cambridge. In my first year I was taught some of this stuff by a Polish logician. I was talking to Laurence about this last night � about how easy it is to get the idea that the foundations of logic and mathematics is too difficult and one should reduce one�s exposure to it to a pure minimum.

On the other hand the epitome of this style of thought is the Tractatus which is really very short � I went out and bought another copy given my first copy is in a pile somewhere. I also downloaded a 1975 article about proposition 3.33 or thereabouts where LW roughs up Russell � who at that point is hanging out with deviants including Keynes, DHL and Hux at Garsington. C makes the point that one of the odd things about English intellectual endeavour at this point is the degree to which everyone is related to everyone else. Anyway using the 1975 retrospective I had a go at proposition 3.33 and decided it was rather good. LW makes the distinction between symbols and signs � and warns against the dangers of recklessly introducing signage � symbols deserve respect. One of the realisations which emerged was that the Theory of Types is alive and well in Computer Science and here they care little for proposition 3.33.

The intervening step is the 1939 Turing-Wittgenstein discussions. Turing worries about bridges falling down because of contradictions and LW tries to tell him not to be so angsty. Its obvious to any user of Microsoft that they have tried to take both points of view on board. They don�t worry over much about contradictions and the software regularly does fall over especially where boundaries intervene. There is an interesting question about why �falling over� constitutes an error, I think, and indeed whether these �errors� have anything to do with enthusiastically embracing the Theory of Types and ignoring proposition 3.33. One of the more conceptual things about Turing machines which I learned last year is that many of them behave in very bizarre ways � in truth they may be artworks. Needless to say a vid has ensued.

I think some of this has to do with the history of mathematics in German Us in the 19C which was where intellectual freedom first saw the light of day. As part of this freedom maths escaped from engineering and science and went its own way looking at itself from ever loftier perspectives and various ideal pictures of maths as a perfect construct emerged. The interesting move was made by Frege � who inspired Russell. Before they let me in to study philosophy they insisted that I read Frege � they must have thought he was really important.

Lurking somewhere at the heart of all of this is the idea of a function � can a function take a proposition as a value? Can you get a propositional form by thinking in terms of functions. What happens if you feed the output of a function back in as an input? LW seems to think there s a limit to doing this at least as far as propositions are concerned or those functions which might help establish propositional form. In other areas feeding the output of a function in as an input leads to those funny blot-like shapes � but I don�t think this happens in the propositional case. Respect for symbolism does strike me as a good motto in all of this and indeed one is reminded of bits of the I Ching.

There�s a conference in Krakow I am beginning to wonder about and I read the outline of a paper by one of the participants. Its about supply chain governance and the management of non-contractual issues across supply chain interfaces. This is a non-trivial issue and last year Toyota learned something from the French on this while collaborating in Central Europe. The issue which the paper identifies is in the different ways of establishing governance across these supply chain interfaces. Governance has to do with agreeing to be bound by rules.

It seems to me that the Microsoft debacle described earlier is most evident at supply chain interfaces. There is something about the ways rules do or don�t get carried across these interfaces that s worth digging deeper around.