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A Scheme Primer
Table of Contents - 1. Introduction - 2.
Scheme's lispy structure is of great benefit here, since as we have learned we can easily quote entire sections of code. The evaluator really is performing the underlying computation, using merely addition (on both positive and negative numbers) and numeric equality check procedures, which we have provided. We also gather all the arg-expr argument expressions passed to this procedure by calling evaluate recursively on each with the current environment, env.
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