単数形
http://markun.cs.shinshu-u.ac.jp/kiso/projects/proofchecker/mizar/Mizar4/printout/mizar4ja_prn.pdf では、
- vocabulary (単数?)
- notation (単数?)
しかし、
Make Environment, Mizar Ver. 8.1.04 (Win32/FPC)
Copyright (c) 1990-2015 Association of Mizar Users**** 1 error detected
environ vocabulary EX03; ::> *210 ::> 210: Wrong item in environment declaration