An inquiry is any process that has the aim of augmenting knowledge, resolving doubt, or solving a problem. A theory of inquiry is an account of the various types of inquiry and a treatment of the ways that each type of inquiry achieves its aim.
When three terms are so related to one another that the last is wholly contained in the middle and the middle is wholly contained in or excluded from the first, the extremes must admit of perfect syllogism. By 'middle term' I mean that which both is contained in another and contains another in itself, and which is the middle by its position also; and by 'extremes' (a) that which is contained in another, and (b) that in which another is contained. For if A is predicated of all B, and B of all C, A must necessarily be predicated of all C. ... I call this kind of figure the First. (Aristotle, Prior Analytics, 1.4)
Inductive reasoning consists in establishing a relation between one extreme term and the middle term by means of the other extreme; for example, if B is the middle term of A and C, in proving by means of C that A applies to B; for this is how we effect inductions. (Aristotle, Prior Analytics, 2.23)
In computer communications, enquiry is a transmission-control character that requests a response from the receiving station with which a connection has been set up. It represents a signal intended to trigger a response at the receiving end, to see if it is still present. The response, and answer-back code to the terminal that transmitted the WRU (who are you) signal, may include station identification, the type of equipment in service, and the status of the remote station.
Some teleprinters had a "programmable" drum, which could hold a 20 or 22 character message. The message was encoded on the drum by breaking tabs off the drum. This sequence could be transmitted upon receipt of an enquiry signal, if enabled, or by pressing the "Here is" key on the keyboard.
In the 1960s, DEC routinely disabled the answerback feature on Teletype Model 33 terminals because it interfered with the use of the paper-tape reader and punch for binary data. However, the DEC VT100 terminals from 1978 responded to enquiry with a user-configurable answerback message, as did its successors.
The PBS provides ''an exhaustive, hierarchical tree structure of deliverables (physical, functional or conceptual) that make up the project, arranged in whole-part relationship'' (Duncan, 2015).
This diagrammatic representation of project outputs provides a clear and unambiguous statement of what the project is to deliver.
The PBS is identical in format to the work breakdown structure (WBS), but is a separate entity and is used at a different step in the planning process. The PBS precedes the WBS and focuses on cataloguing all the desired outputs (products) needed to achieve the goal of the project. This feeds into creation of the WBS, which identifies the tasks and activities required to deliver those outputs. Supporters of product based planning suggest that this overcomes difficulties that arise from assumptions about what to do and how to do it by focusing instead on the goals and objectives of the project - an oft-quoted analogy is that PBS defines where you want to go, the WBS tells you how to get there.
Let C be a category with some objects X1 and X2. An object X is a product of X1 and X2, denoted X1 × X2, if it satisfies this universal property:
The unique morphism f is called the product of morphismsf1 and f2 and is denoted < f1, f2 >. The morphisms π1 and π2 are called the canonical projections or projection morphisms.
Above we defined the binary product. Instead of two objects we can take an arbitrary family of objects indexed by some set I. Then we obtain the definition of a product.
An object X is the product of a family (Xi)i∈I of objects iff there exist morphisms πi: X → Xi, such that for every object Y and a I-indexed family of morphisms fi: Y → Xi there exists a unique morphism f: Y → X such that the following diagrams commute for all i∈I: