Example of a statement in the Klerer–May programming language
For input and output, the Klerer–May system used a Friden Flexowriter modified to allow half-line motions for subscripts and superscripts.[1] The character set included digits, upper-case letters, subsets of 14 lower-case Latin letters and 18 Greek letters, arithmetic operators (+−×/|) and punctuation (.,()), and eight special line-drawing characters (resembling ╲╱⎜_⎨⎬˘⁔) used to construct multi-line brackets and symbols for summation, products, roots, and for multi-line division or fractions.[2]
The system was intended to be forgiving of input mistakes, and easy to learn; its reference manual was only two pages.[3]
Klerer, Melvin; May, Jack (1965). "Two-dimensional Programming". Proceedings of the November 30--December 1, 1965, Fall Joint Computer Conference, Part I. Fall Joint Computer Conference. Las Vegas, Nevada: ACM. pp. 63–75. doi:10.1145/1463891.1463897.
Klerer, Melvin; Grossman, Fred (November 1967). "Further Advances in Two-dimensional Input-output by Typewriter Terminals". Proceedings of the November 14–16, 1967, Fall Joint Computer Conference. Fall Joint Computer Conference. Anaheim, California: ACM. pp. 675–687. doi:10.1145/1465611.1465701.