Apologies for a question that is specific to one country (but perhaps others find it a curious example of how mathematical notation can vary between countries).
In Finnish calculus texts, if $F$ is an antiderivative of $f$, it is customary to write a definite integral as $$ \int_a^b f(x) \; dx = \bigg/_{\!\!\!\!a}^{\,b} F(x) $$ where the right hand side means $F(b)-F(a)$.
Q: When and where did this Finnish notation originate, and how did it spread?
As far as I know, this notation is not used anywhere outside Finland, and indeed Latex does not support it very well. (Finnish mathematicians simulate it with a big $/$ operator and tweak the spacing of the limits.) Elsewhere the typical notations are $$ F(x) \Big|_{x=a}^b \qquad\text{and}\qquad \Big[ F(x) \Big]_{x=a}^b $$ possibly with the "$x=$" omitted.
The earliest occurrence I know is in Ernst Lindelöf's ''Johdatus korkeampaan analyysiin'' (3rd printing, 1942, page 363).
Lindelöf simply introduces the notation here, but offers no explanation on whether it is already common. I wonder if this is the first use or if it is in fact older.
