SEMIPAL 2(ID:7816/)

Extension of the original SEMIPAL notation, permitting labels
Related languages
SEMIPAL => SEMIPAL 2   Extension of
References:
  • de Bruijn, N.G. "SEMIPAL 2, an extension of the mathematical language SEMIPAL" Notitie 1969/43 March 1969 Department of Mathematics, Eindhoven University of Technology view details Abstract: SEMIPAL is a simple language, or rather a notational system for the abbreviation of expressions. [...] In this note we shall extend that language by extending the notion of the indicator strings used in SEMIPAL.
    In SEMIPAL every line represents the definition of a new identifier in terms of previously introduced ones, as far as the new identifier was not introduced as a variable or as a primitive notion. And every line has a context indicator, which is either 0 or a previous block opener. If the indicator of a line is xn, and if , for every j (I G j 4 n) , x is the indicator of the line whose identifier is x and if 0 is the indicator of  the line whose identifier is x, , then (x, , . . . ,x ) is called the indicator string of the given line.
    With this definition of the indicator strings, the following property holds. If ( x , x ) and (y ,… ,Ym) are the indicator strings of two different lines, then there is an integer k (0 G k S min(n,m) ) such that x = yl ,…,% = yk, and such that there is no further case where an x equals any In the extended form of SENIPAL, to be discussed presently, this property no longer holds, and the indicator strings can no longer be obtained from single indicators. In SEMIPAL 2, as we shall call this version, we shall write an indicator string in front of every line, and no longer a single indicator.