paralell assignment problem
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Date:   (:) 
From:  skaller <skaller@u...> 
Subject:  paralell assignment problem 
Does anyone know how to solve the parallel assignment problem? Name invented by me to describe this problem: x1,x2,x3..xn = e1,e2,e3 .. en where ei might contain the variables xj. (Note = here is assignment). The solution is a sequence of assignments involving only xi, ei, and ti, where ti are temporaries introduced to save the values of the expressions. For example, a solution to x,y = y,x is t = x; x = y; y = t I seek a solution which minimises the number of assignments. Note that the relation i < j == ej doesn't depend on xi is not transitive. This (a) confuses me enough I can't see the solution, and (b) is precisely what allows a temporary to remove a dependence.  John Skaller, mailto:skaller@users.sf.net voice: 061296600850, snail: PO BOX 401 Glebe NSW 2037 Australia Checkout the Felix programming language http://felix.sf.net