Minimal Search

最小探索の仕組み

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以前の投稿でWorkSpace (WS)について見た.

このWorkSpaceは, 近年のミニマリスト・プログラムにおいて中核をなす新しい発想であると言える. そのWorkSpaceにおける「最小探索（Minimal Search）」の仕組みについて, 今回は改めてまとめてみたい.

(13) WS = [a, {b, c}]

[…]

The elements a and {b, c} are members of the WS (13) and are thus also terms of that WS. The objects b and c, on the other hand, are terms of the WS, not members of it. Let’s adopt ‘term of’ in order to have a vocabulary to more fully detail the concept of Minimal Search.

Search operates in a stepwise fashion: it first locates some P (from the WS), and in a second step locates some Q to merge with P. Applied to the WS in (13), that is, [a, {b, c}], Merge will first locate P, where P can be any member of [a, {b, c}], so either a or {b, c}. Members of the WS are all equally available with Least Search; the members are the first objects found looking into the WS and the first Search step can take any one of the members. The terms b and c in (13) are not members of that WS and hence are not candidates for (first-step) Search.

(Chomsky et al., 2023, p. 19)

これを確認すると分かるが, MergeはWSの深いところにある要素をいきなり掴むことはできず, まず表面にあるMember（構成員）から選ばなければならないという計算上の制約が課されることになる.

つまり, 理論構築の際, この制約を意識しながら理論を構築する必要がある. もしくは, これを仮定しない場合, なぜその仮定が不要になるのかといった検討が必要になるであろう.

参考文献

• Chomsky, N., Seely, T. D., Berwick, R. C., Fong, S., Huybregts, M. A. C., Kitahara, H., McInnerney, A., & Sugimoto, Y. (2023). Merge and the strong minimalist thesis. Cambridge University Press.