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In the paper typed and untyped λ-terms are considered. Typed λ-terms use variablesof any order and constants of order ≤1. Constants of order 1 are strong computablefunctions with indeterminate values of arguments and every function has an untyped λ-term that λ-defines it. The so-called canonical notion of δ-reduction is introduced.This is the notion of δ-reduction that is used in the implementation of functionalprogramming languages. For the canonical notion of δ-reduction the translation of typed λ-terms into untyped λ-terms is studied.