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A Syntactic Device (called a "syndev" for short) is a tool, such as a computer or jeejah, which is capable of manipulating values. Compare it to a semantic device, like a human brain, which is capable of not only manipulating values, but attaching them to deeper concepts.

The name "Syntactic Device" and its dualism with the concept of Semantic Device is perhaps rooted in the similar dualism that exists between Mathematics and Computing Science which may be considered as sister sciences provided that one interprets Gödel's [Completeness Theorem] as the link that binds them together. In this setting, Mathematics embodies the semantic aspect and Computing Science embodies the syntactic aspect.