fix typo / algorithm name

spec.html

@@ -47,7 +47,7 @@ <h1>Math.sum ( ..._args_ )</h1>
     1. If _state_ is ~minus-infinity~, return *-∞*<sub>𝔽</sub>.
     1. If _state_ is ~minus-zero~, return *-0*<sub>𝔽</sub>.
     1. Return 𝔽(_sum_).
-    1. NOTE: The value of _sum_ can be computed without arbitrary-precision arithmetic by a variety of algoirthms. One such is the "Expansion Sum" algorithm given in <i>Adaptive Precision Floating-Point Arithmetic and Fast Robust Geometric Predicates</i> by Jonathan Richard Shewchuk.
+    1. NOTE: The value of _sum_ can be computed without arbitrary-precision arithmetic by a variety of algorithms. One such is the "Grow-Expansion" algorithm given in <i>Adaptive Precision Floating-Point Arithmetic and Fast Robust Geometric Predicates</i> by Jonathan Richard Shewchuk.
   </emu-alg>
   <p>The *"length"* property of this function is *2*<sub>𝔽</sub>.</p>
 </emu-clause>