Update README.md

Author: DanielVandH

README.md

@@ -8,7 +8,7 @@ The package provides four predicates. In the functions below, all the inputs sho
 - `orient2(pa, pb, pc)`: Given three points `pa`, `pb`, and `pc` in two dimensions, returns a positive value if the points are in counter-clockwise order; a negative value if they occur in clockwise order; and zero if they are collinear. Equivalently, returns a positive value if `pc` is left of the oriented line from `pa` to `pb`; a negative value if `pc` is right of this line; and zero if they are collinear.
 - `orient3(pa, pb, pc, pd)`: Given four points `pa`, `pb`, `pc`, and `pd` in three dimensions, define the oriented plane on which the triangle `(pa, pb, pc)` is positively oriented. Returns a positive value if `pd` is below this plane; a negative value if `pd` is above this plane; and zero if the points are coplanar.
 - `incircle(pa, pb, pc, pd)`: Given four points `pa`, `pb`, `pc`, and `pd` in two dimensions, returns a positive value if `pd` is inside the circle through `pa`, `pb`, and `pc`; a negative value if `pd` is outside this circle; and zero if `pd` is on the circle.
-- `insphere(pa, pb, pc, pd, pe)`: Given five points `pa`, `pb`, `pc`, `pd`, and `pe` in three dimensions, returns a positive value if `pe` inside on the sphere through `pa`, `pb`, `pc`, and `pd`; a negative value if `pe` is outside this sphere; and zero if `pe` is on the sphere.
+- `insphere(pa, pb, pc, pd, pe)`: Given five points `pa`, `pb`, `pc`, `pd`, and `pe` in three dimensions, returns a positive value if `pe` inside of the sphere through `pa`, `pb`, `pc`, and `pd`; a negative value if `pe` is outside this sphere; and zero if `pe` is on the sphere.
 
 We also define the functions `orient2p`, `orient3p`, `incirclep`, and `inspherep` which simply return the sign of the corresponding predicate. For example,
 ```julia-repl