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Checking domain

SYNTAX: Notion in checking theory. Informally, the checking domain of a head A consists of everything adjoined to it, and of its specifier(s). Formally, the checking domain of a head A is defined as the minimal residue of A. The residue of A is its domain minus its complement domain. EXAMPLE: In the following structure (with a head H adjoined to X), the checking domain of X consists of UP, ZP, WP and H. The checking domain of H is UP, ZP and WP.

       XP1
       /\
      /  \
     UP  XP2
        /\
       /  \
     ZP1    X'
    /\      /\
   /  \    /  \
  WP  ZP2  X1  YP
          /\
         /  \
        H   X2