˝˝ DOUBLE ACUTE ACCENT
ΑΑ GREEK CAPITAL LETTER ALPHA
ΒΒ GREEK CAPITAL LETTER BETA
+ ΓΓ GREEK CAPITAL LETTER GAMMA
ΔΔ GREEK CAPITAL LETTER DELTA
ΕΕ GREEK CAPITAL LETTER EPSILON
ΖΖ GREEK CAPITAL LETTER ZETA
ΟΟ GREEK CAPITAL LETTER OMICRON
ΠΠ GREEK CAPITAL LETTER PI
ΡΡ GREEK CAPITAL LETTER RHO
+ ΣΣ GREEK CAPITAL LETTER SIGMA
ΤΤ GREEK CAPITAL LETTER TAU
ΥΥ GREEK CAPITAL LETTER UPSILON
ΦΦ GREEK CAPITAL LETTER PHI
∂∂ PARTIAL DIFFERENTIAL
∃∃ THERE EXISTS
∅∅ EMPTY SET
+ ∇∇ NABLA
∈∈ ELEMENT OF
+ ∉∉ NOT AN ELEMENT OF
∋∋ CONTAINS AS MEMBER
−− MINUS SIGN
∓∓ MINUS-OR-PLUS SIGN