Just as forecasted, the comments degenerate towards the inebriated category… But so far restricted to my Italian readers! I meant bar as in “bar of a tribunal”, not as “drunken bar fights”!!!

]]>:-] ]]>

Shafer, Glenn and Vladimir Vovk (2006). The sources of Kolmogorovâ€™s Grundbegriffe. Statistical Science 21: 70-98.

And indeed Shafer and Vovk indicate Jeffreys (1931) as the origin of the notation. This paper is actually very interesting in terms of the discussion of Burdzy’s book as it also covers the notion of collectives whom refutation the authors attribute to Ville (1939).

]]>“H. McColl, Proc. Lond Math. Soc. 11, 113 (1880). McColl uses the symbol $x_a$ for the probability of the proposition $x$ on the hypothesis $a$.”

]]>I fear this historical debate is soon going to degenerate into bar fights!!!

]]>in this perspective, Jeffreys was the one who found the bar!!! ]]>