A Proposal for Definitions in ALGOL An extension to ALGOL is proposed for adding new data types and operators to the language. Definitions may occur in any block heading and terminate with the block. They are an integral part of the program and are not fixed in the language. Even the behavior of existing operators may be redefined. The processing of text containing defined contexts features a "replacement rule" that eliminates unnecessary iterations and temporary storage. Examples of definition sets are given for real and complex matrices, complex numbers, file processing, and list manipulation. CACM April, 1967 Galler, B. A. Perlis, A. J. CA670401 JB February 28, 1978 11:43 AM 1086 4 1614 1132 4 1614 1234 4 1614 1263 4 1614 1265 4 1614 1270 4 1614 1323 4 1614 1358 4 1614 1379 4 1614 1380 4 1614 1453 4 1614 1464 4 1614 1484 4 1614 1491 4 1614 1498 4 1614 1613 4 1614 1614 4 1614 1614 4 1614 1781 4 1614 1825 4 1614 1860 4 1614 2083 4 1614 2178 4 1614 2179 4 1614 2252 4 1614 2253 4 1614 2325 4 1614 2341 4 1614 2546 4 1614 2557 4 1614 2645 4 1614 2652 4 1614 2684 4 1614 2842 4 1614 2929 4 1614 2934 4 1614 3069 4 1614 669 4 1614 679 4 1614 691 4 1614 761 4 1614 949 4 1614 989 4 1614 1614 5 1614 1614 5 1614 1614 5 1614 1693 5 1614 1781 5 1614 1824 5 1614 1861 5 1614 2126 5 1614 437 5 1614 3184 5 1614 823 6 1614 123 6 1614 196 6 1614 196 6 1614 919 6 1614 990 6 1614 1007 6 1614 1046 6 1614 1131 6 1614 1139 6 1614 1140 6 1614 1149 6 1614 1198 6 1614 1215 6 1614 1223 6 1614 1265 6 1614 1303 6 1614 1323 6 1614 1358 6 1614 1358 6 1614 1366 6 1614 1421 6 1614 1421 6 1614 1460 6 1614 1462 6 1614 1463 6 1614 1467 6 1614 1468 6 1614 1477 6 1614 1477 6 1614 1491 6 1614 1491 6 1614 1496 6 1614 1531 6 1614 1535 6 1614 1565 6 1614 1601 6 1614 1602 6 1614 1613 6 1614 1614 6 1614 1614 6 1614 1614 6 1614 1614 6 1614 1614 6 1614 1626 6 1614 1641 6 1614 1693 6 1614 1781 6 1614 1781 6 1614 1787 6 1614 1788 6 1614 205 6 1614 224 6 1614 249 6 1614 288 6 1614 316 6 1614 381 6 1614 398 6 1614 11 6 1614 404 6 1614 404 6 1614 404 6 1614 408 6 1614 410 6 1614 463 6 1614 464 6 1614 483 6 1614 3184 6 1614 3188 6 1614 584 6 1614 600 6 1614 680 6 1614 691 6 1614 763 6 1614 799 6 1614