A calculator to perform boolean algebra operations and simplifications element-wise on matrices. Built with Common Lisp, and compiled with CLISP 2.49.60+.
For example, a 2 x 3 matrix, A, containing the elements (from left to right, top to bottom) of a, b, c, d, e, f, is represented as the following list of lists:
(setq A '((a b c) (d e f)))
That is, A is a list containing 2 lists, with each of these lists containing 3 elements. We can extend this representation for any n x m matrix.
The calculator performs simplifications on each element of a given matrix according to boolean algebra laws (uses a rewrite system), with AND (b-and), OR (b-or) and NOT (b-not) operators. The following boolean algebra laws are implemented:
- Annulment:
(b-and x 0)=0(b-or x 1)=1
- Identity:
(b-and x 1)=x(b-or x 0)=x
- Idempotent:
(b-and x x)=x(b-or x x)=x
- Complement:
(b-and x (b-not x))=0(b-or x (b-not x))=1
- Absorption:
(b-and (b-or a b))=a(b-or (b-and a b))=a
- Double negation:
(b-not (b-not x))=x - Distributive:
(b-or a (b-and b c))=(b-and (b-or a b) (b-or a c))(b-and a (b-or b c))=(b-or (b-and a b) (b-and a c))
- Associative:
(b-or (b-or a b) c)=(b-or a (b-or b c))(b-and (b-and a b) c)=(b-and a (b-and b c))
- De Morgan's:
(b-not (b-and a b))=(b-or (b-not a) (b-not b))(b-not (b-or a b))=(b-and (b-not a) (b-not b))
For example, given the element (b-or (b-and x y) (b-and x (b-not y))) in some matrix, this can be simplified as follows:
(b-or (b-and x y) (b-and x (b-not y)))
= (b-and x (b-or y (b-not y))) (distributive)
= (b-and x 1) (complement)
= x (identity)
Consequently, a call to b-simplify with some n x m matrix with every matrix element containing this boolean expression will result in an n x m matrix with every element containing x.
The testing suite provides valid and invalid inputs for each function, ensuring that expected and unexpected results are covered. Tests can be run by executing the tests.lisp file, which will provide a printout of test results in stdout.
Example of test output for b-check-shape:
b-check-shape
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PASS ✓ - valid : ((X))
PASS ✓ - valid : ((1 2 3) (X Y Z) (A B C))
PASS ✓ - valid : ((1 2 3 4 5))
PASS ✓ - valid : ((1) (1) (1) (1))
PASS ✓ - invalid : ((1 2 3) (X Y Z) (A B C D))
PASS ✓ - invalid : ((1 2) (X Y Z) (A B C))
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Expected output for remaining tests can be found in testsExpected.txt.