Báo cáo khoa học: A Type of Program for Mechanical Translation

A program for the mechanical translation of a limited French vocabulary into English was constructed for operation on the computer APEXC. Its principal features were an improved routine for dictionary look-up, and an organization permitting systematic incorporation of additional subroutines.
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Báo cáo khoa học: " A Type of Program for Mechanical Translation" [Mechanical Translation, vol.4, no.3, December 1957; pp. 54-58]A Type of Program for Mechanical TranslationJ. P. Cleave, University of Southampton, Southampton, England* A p rogram for the mechanical translation of a limited French vocabulary into Eng- l ish was constructed for operation on the computer APEXC. Its principal features w ere an improved routine for dictionary look-up, and an organization permitting s ystematic incorporation of additional subroutines. A program for syntactic p rocessing was constructed but was too large for the available storage space. I t examined preceding and following items — stems or endings — in order to c hoose correct equivalents, and used a dictionary of syntactic sequences or s tructures to effect local word-order change. APEXC A PEXC has one branch (jump) instruction d iscriminating between positive (or zero) and T he computer has a magnetic drum store negative.w ith 1024 locations arranged in 32 tracks each T he following abbreviations will be used:o f 32 locations. Each location contains 32 bits.A ny location can therefore be specified by an Ox operand address (X-address) of ana ddress of 10 bits. Both data and instructions instruction O.a re stored on the drum. Oy next instruction address (Y-address) of O. A n instruction consists of 32 binary digits and (Ox)ls least significant digit of Ox (i.e.,s pecifies an operation (function), the 10 bit ad- digit 10).d ress of an operand contained in the store and (Oy)ms most significant digit of Oy (i.e.,t he address (10 bits) of the next instruction, digit 11).w hich again is contained in one location in the (z) contents of the location whose addresss tore. The arrangement of the digits of an in- is z.s truction is shown below (Fig. 1). Dictionary Subroutines The dictionary procedure is best explained by considering a simplified example with a diction-* T his paper is a report of work done in ary of 16 positive entries stored in increasingc ooperation with Dr. A. D. Booth and Mr. L. numerical order in locations 1, 2, 3, ... 16.B randwood at the Computational Laboratory, Suppose W is a word, known to be in the dic-Birkbeck College, London. tionary, whose address in the dictionary is required. Program for MT 55 Figure 2The bracketing procedure1 requires us to start If we now examine the dictionary entry specifiedin the middle of the dictionary, either at 8 or 9. by Ox at the beginning of operation 4, it canS uppose 8 is chosen; the procedure for 9 is be seen that W is either in Ox or Ox + 1 . (Ifanalogous (see Fig. 2). the initial location had been 9, the alternatives would be Ox and Ox - 1.) Hitherto, dictionary An operation consists of forming W-(y) by subroutines we have used counted the number ofm eans of a subtraction instruction O. If the operations performed and at the final operationresult is positive, a probe-number p is added tested Ox and its neighbor for identity with W.to Ox , if negative it is subtracted, p is then T his latter test had to be synthesized and sodivided by 2. required several instructions. This disadvan- T he first operation is on (8) (i.e., O x = 8 ) tage can be eliminated if the final operation is s imilar to its predecessors.with p = 22 . After the operation ...