Compounds of 合う

• 切磋琢磨し合う
  (exp) to work hard together
  to be in a state of friendly rivalry
• 連絡を取り合う
  (exp,v5u) to keep in contact (e.g. by phone, mail, etc.)
  to keep in touch
• 袖振り合うも他生の縁
  (exp) (id) A meeting by chance is preordained