If you have a sister and she dies, do you stop saying you have one? Or are you always a sister, even when the other half of the equation is gone?

I've made the most important discovery of my life. It's only in the mysterious equation of love that any logical reasons can be found.
John Forbes Nash (portrayed by Russell Crowe, in A Beautiful Mind (2001).Von Neumann languages do not have useful properties for reasoning about programs. Axiomatic and denotational semantics are precise tools for describing and understanding conventional programs, but they only talk about them and cannot alter their ungainly properties. Unlike von Neumann languages, the language of ordinary algebra is suitable both for stating its laws and for transforming an equation into its solution, all within the "language."
john backusAn ideological movement is a collection of people many of whom could hardly bake a cake, fix a car, sustain a friendship or a marriage, or even do a quadratic equation, yet they believe they know how to rule the world. The university, in which it is possible to combine theoretical pretension with comprehensive ineptitude, has become the natural habitat of the ideological enthusiast. A kind of adventure playground, carefully insulated from reality in order to prevent absentminded professors from bumping into things as they explore transcendental realms, has become the institutional base for civilizational selfhatred.
kenneth minogue...where Nietzsche’s response to the equation of socialism and morality was to question the value of morality, at least as it had been customarily understood, economists like Mises and Hayek pursued a different path, one Nietzsche would never have dared to take: they made the market the very expression of morality.
ludwig von misesOne day he was explaining a relation to me; then he suddenly turned round and said, "Sir, an equation has no meaning for me unless it expresses a thought of GOD."
Shiyali Ramamrita Ranganathan, in Ramanujan, the Man and the Mathematician (1967), p. 88Instead, we try to apply Aesop 's 2,600yearold equation to opportunities in which we have reasonable confidence as to how many birds are in the bush and when they will emerge (a formulation that my grandsons would probably update to "A girl in a convertible is worth five in the phonebook.").
warren buffettMan is naturally selfcentered and he is inclined to regard expediency as the supreme standard for what is right and wrong. However, we must not convert an inclination into an axiom that just as man's perceptions cannot operate outside time and space, so his motivations cannot operate outside expediency; that man can never transcend his own self. The most fatal trap into which thinking may fall is the equation of existence and expediency.
abraham joshua heschelIn the social equation, the value of a single life is nil; in the cosmic equation, it is infinite... Not only communism, but any political movement which implicitly relies on purely utilitarian ethics, must become a victim to the same fatal error. It is a fallacy as naïve as a mathematical teaser, and yet its consequences lead straight to Goya's Disasters, to the reign of the guillotine, the torture chambers of the Inquisition, or the cellars of the Lubianka.
Arthur KoestlerThe critical element in this equation is developing inclusiveness that envelopes all these competing priorities (of the different ethnic groups) in a manner that is fair to all. Without it we risk remaining a divided society all the more tragic for having unfulfilled our potential.
ratu joni madraiwiwiThere was a comfort in the thought, a strange sort of personal comfort in being able to believe that some intelligence might have solved the riddle of that mysterious equation of the universe. And how, perhaps, that mysterious equation might tie in with the spiritual force that was idealistic brother to time and space and all those other elemental factors that held the universe together.
clifford d. simakAlbert Einstein described the lefthand side of the equation for his general theory of relativity as built on granite , the righthand side on sand.
Quoted in p.33 (Sand: The Neverending Story)A great deal of the thinking [in Organizational Development] has been influenced by cybernetics and information theory, though this has been used as much to extend the scope of closedsystem as to improve the sophistication of open system formulations. It was von Bertalanffy (1950) who, in terms of the general transport equation which he introduced, first fully disclosed the importance of openness or closedness to the environment as a means of distinguishing living organisms from inanimate objects.
Fred Emery and Eric Trist (1963) "The Causal Texture of Organizational Environments". In: Human Relations, 18: p. 22One of the most frequently mentioned equations was Euler's equation, Respondents called it "the most profound mathematical statement ever written"; "uncanny and sublime"; "filled with cosmic beauty "; and "mindblowing". Another asked: "What could be more mystical than an imaginary number interacting with real numbers to produce nothing ?" The equation contains nine basic concepts of mathematics once and only once in a single expression. These are: e (the base of natural logarithms); the exponent operation; ?; plus (or minus, depending on how you write it); multiplication; imaginary numbers; equals; one; and zero.
Robert P. Crease, in "The greatest equations ever" at PhysicsWeb (October 2004)Like a Shakespearean sonnet that captures the very essence of love, or a painting that brings out the beauty of the human form that is far more than just skin deep, Euler's equation reaches down into the very depths of existence.
Keith Devlin, as quoted in Dr. Euler's Fabulous Formula : Cures Many Mathematical Ills (2006) ISBN 9780691118222One of the most frequently mentioned equations was Euler 's equation, Respondents called it "the most profound mathematical statement ever written"; "uncanny and sublime"; "filled with cosmic beauty "; and " mind blowing". Another asked: "What could be more mystical than an imaginary number interacting with real numbers to produce nothing ?" The equation contains nine basic concepts of mathematics once and only once in a single expression. These are: e (the base of natural logarithms); the exponent operation; ?; plus (or minus, depending on how you write it); multiplication; imaginary numbers; equals; one; and zero.
Robert P. Crease, in "The greatest equations ever" at PhysicsWeb (October 2004)A great deal of the thinking [in Organizational Development] has been influenced by cybernetics and information theory, though this has been used as much to extend the scope of closedsystem as to improve the sophistication of open system formulations. It was von Bertalanffy (1950) who, in terms of the general transport equation which he introduced, first fully disclosed the importance of openness or closedness to the environment as a means of distinguishing living organisms from inanimate objects.
Fred Emery and Eric Trist (1963) "The Causal Texture of Organizational Environments". In: Human Relations, 18: p. 22Today's scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality.
Nikola Tesla (1934) cited in: Cheney, Uth & Glenn (1999) Tesla: master of lightning. p.137Let us suppose that we have set the problem of finding a solution to the equation This is a problem for which the Babylonians around 1700 BC found the excellent approximation ...This is the identical problem which Pythagoras asserted had no fractional solution and in whose honor he was supposed to have sacrificed a hecatomb of oxen the problem which caused the existentialist crisis in ancient Greek mathematics. The exists (as the diagonal of the unit square); yet it does not exist (as a fraction)!
Philip J. Davis and Reuben Hersh, The Mathematical Experience (1980) p.180No matter how effective your rebuttal may seem to be to you, a response will "bump" the problem into greater prominence and relevance in the search engine results, which then turns your headache into a migraine. This is doubly dangerous since "bumping" the negative information potentially introduces the "Streisand Effect" into the equation, which is something to avoid if at all possible. It is commonly defined as a phenomenon in which an attempt to censor or remove a piece of information on the web backfires, causing greater publicity.
John W. Dozier, Sue Scheff (2009). Google Bomb: The Untold Story of the $11.3M Verdict That Changed the Way We Use the Internet. HCI. p. 40. ISBN 0757314155.