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I have a large number of expressions which I am trying to solve.

  • List 1 contains formulas like A = B + C.
  • List 2 contains additional equations for those variables, like C = D*3, C = B/2, B = D*50, etc.
  • List 3 contains values for those variables B, D, etc.

I then need to compute all possible results for the List 1 formulas when expanding the formula by using different equations from List 2. Since these lists are large, the number of possible combinations can be huge!

I planning to break down the problem as follows:

  1. For each expression in List-1 look up all possible values for each variable in List-2 and generate all possible expression as List-4. List-4 can be huge, maybe in GB or TB!
  2. Create a tree for each expression from first generated list Find the each variable values in List-3.
  3. Replace constant in the expression to get the result.

Step 1 and 3 are the core problems which needs lot of memory and CPU, any guidance would be highly appreciated.

Example:

  • List1 (Expressions): A = x + y, y = u + v
  • List2 (extensions): v = 20 + u, v = 30*u
  • List3 (constant values): x = 20, u = 10

Expanding with v = 20 + u:
A = x + y, y = u + 20 + u, x = 20, u = 10
=> y = 40, A = 60

Expanding with v = 30*u:
A = x + y, y = u + 30*u, x = 20, u = 10
=> y = 310, A = 330

closed as unclear what you're asking by gnat, amon, Bart van Ingen Schenau, BobDalgleish, MetaFight Dec 13 '17 at 17:14

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    please don't cross-post: stackoverflow.com/questions/47566167/… – gnat Nov 30 '17 at 5:53
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    It's not clear to me the relationship between List-1, List-2, and List-3. Is List-1 and List-2 one to one or many to one? Same question for List2 and List3. – Neil Nov 30 '17 at 8:46
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    For me it's not clear either. Am I correctly assuming that list 2 just contains variable names, that list 3 contains tuples of values for he variables in list 2, and that expressions in list 1 are considered independent from each other ? – Christophe Nov 30 '17 at 9:14
  • What's the difference between: "formulas" in list 1 written as assignments (or equalities?) involving variables -- vs. -- "values" written in list 2, also as assignments (or equalities?) involving variables? – Erik Eidt Nov 30 '17 at 18:06
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    Also we need to be clear on when/whether the elements in the various lists (not to mention all the lists as a whole) are taken in conjunction or disjunction. – Erik Eidt Nov 30 '17 at 18:07

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