<Multi_key> <equal> <equal> : "≡" U2261 # IDENTICAL TO
<Multi_key> <colon> <equal> : "≔" U2254 # COLON EQUALS
<Multi_key> <equal> <colon> : "≕" U2255 # EQUALS COLON
+<Multi_key> <p> <r> <o> <p> : "∝" U221D # PROPORTIONAL TO
# Using <slash> conflicts.
<Multi_key> <equal> <bar> <equal> : "≢" U2262 # NOT IDENTICAL TO
# We already have ±