"Well-Defined". From MathWorld – A Wolfram Web Resource. Retrieved 2 January 2013. ↑ Joseph J. Rotman, The Theory of Groups: an Introduction, p. 287 "... a function is "single-valued," or, as we prefer to say ... a function is well defined.", Allyn and Bacon, 1965. ↑ "Operator Precedence and Associativity in C".