HP Prime Graphing Calculator - Manual (Page 418)

414 Functions and commands
reflection With a line (D) and a point (C) as arguments, returns the
reflection of the point across the line (i.e. the line is taken as
a line of symmetry). With a point (A) and a curve (C) as
arguments, returns the reflection of the curve about the point
(i.e. the point is taken as the point of symmetry).
reflection((Pnt(A) or Line(D)),(Pnt(C) or
Curve(C)))
Example:
reflection(line(x=3),point(1,1))
reflects the point
at (1, 1) over the vertical line x=3 to create a point at (5,1)
remove Returns a list with the elements that satisfy the Boolean
function removed.
remove(FncBool(f)||e,Lst(l))
Example:
remove(x->x>=5,[1,2,6,7])
gives
[1,2]
reorder Reorders the in an expression according to the order given in
LstVar.
reorder(Expr,LstVar)
Example:
reorder(x^2+2*x+y^2,[y,x])
gives
y^2+x^2+2*x
REPEAT Used in programming to indicate a statement or statements
that should be repeated until a given condition is true.
residue Returns the residue of an expression at a.
residue(Expr,Var(v),Cplx(a))
Example:
residue(1/z,z,0)
gives
1
restart Purges all the variables.
restart(NULL)
resultant Returns the resultant (i.e. the determinant of the Sylvester
matrix) of two polynomials.
resultant(Poly,Poly,Var)
RETURN Used in programming return a value of a function at a certain
point.
return(Expr)