agreement
可算=a mutually agreed arrangement
不可算= mutual understanding
Pacific Rim nations on Friday reached agreement on a joint statement on global warming... (アジア太平洋諸国首脳は金曜日に地球温暖化対策に間する共同声明につき合意を調えた)
http://eng.alc.co.jp/newsbiz/hinata/2007/09/agreementagreem.html