What does left-to-right associativity mean?

Question

I am confused about the definition of left-to-right and right-to-left associativity. I have also seen them called left associativity and right associativity and would like t

Answer 1

a = (x * y) * z is left-to-right and a = x * (y * z) is right-to-left.

glm's matrix multiplcation associates left-to-right because it overloads the * operator. The issue here is about the meaning of the matrix multiplications in terms of geometrical transformations, rather than the mathematical associativity.