Multi-Level Logic: CAD Tools for Simplification

Substitution: function G into function F, express F in terms of G

F = A + B C

G = A + B

F rewritten in terms of G:

F = G (A + C)

Collapsing: reverse of substitution; use to eliminate levels to meet

timing constraints

F = G (A + C)

= (A + B) (A + C)

= A A + A C + A B + B C

= A + B C ¦

(5 literals)

(2 literals)

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