• The properties of executability and universality associated with programming languages can be combined, in a single language, with the well-known properties of mathematical notation which make it such an effective tool of thought.

    Kenneth E. Iverson: The properties of executability and universality associated with programming languages can be combined, in a single language, with the well-known properties of mathematical notation which make it such an effective tool of thought.
    "Notation as a Tool of Thought". Cvommunications of the ACM, 23 (8), (pp. 444 - 465), August 1980.