Sign, symbol 
Quantity 
= 
equal to 
≠ 
not equal to 
≡ 
identically equal to 
Δ 
corresponds to 
≈ 
approximately equal to 
→ 
approaches 
∝ 
proportional to 
∞ 
infinity 
< 
smaller than 
> 
larger than 
≤ 
smaller than or equal to 
≥ 
larger than or equal to 
a 
magnitude of a 
a^{n} 
a raised to the power n 
square root of a 

mean value of a 

p! 
factorial p (1 × 2 × 3 × . . . × p) 
binomial coefficient 

Σ 
Sum 
Π 
Product 
f(x) 
function f of the ... 
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