An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

A abbreviated notation for various functions associated with quadratic differential forms. Each Christoffel symbol is essentially a triplet of three indices, i, j and k, where each index can assume values from 1 to 2 for the case of two variables, or from 1 to n in the case of a quadratic form in n variables. Christoffel symbols appear in many calculations in geometry where non-Cartesian coordinates are used. These symbols are fundamental in the study of tensor analysis.

Named after Elwin Bruno Christoffel (1829-1900), a German mathematician; → symbol.

In a → formal language, a letter used to describe a → predicate or → relation. Also called → relation symbol.

→ predicate; → symbol.

An upper case letter, e.g. "A," "B," "C," etc. representing a → proposition. Propositional symbols are divisible into two sorts: → propositional constants and → propositional variables.

→ propositional; → symbol.

Same as → predicate symbol.

→ relation; → symbol.

1) Something that stands for or represents something else, especially an object representing an abstraction.
2) A conventional sign or character that represents something in a specific context, e.g. an operation or quantity in mathematics or music.

M.E., from L.L. symbolum "creed, token, mark," from Gk. symbolon "sign, mark," from → syn- "together" + stem of ballein "to throw."

Namâd variant of namud, nemud past stem of nemudan "to show;" Mid.Pers. nimūdan, nimây- "to show," from O.Pers./Av. ni- "down; into," → ni- (PIE), + māy- "to measure;" cf. Skt. mati "measures," matra- "measure;" Gk. metron "measure;" L. metrum; PIE base *me- "to measure."

Of or relating to a symbol or symbols; serving as a symbol.

→ symbol; → -ic.

A modern development of → formal logic based on a system of → symbols and → axiomatics in accordance with precise rules. It uses a formalized → artificial language to avoid the ambiguities and logical inadequacies of → natural languages. Symbolic logics are → polyvalent when they admit → truth values other than → true and → false.

→ symbolic; → logic.