Original sentence: Beginning in the early 1960s the new educational doctrine was installed, not only in the USA, but all over the developed world.The idea behind this was that if the axiomatic foundations of mathematics were introduced to children, they could easily cope with the theorems of the mathematical system later
Edited sentence: Beginning in the early 1960s the new educational doctrine was installed, not only in the USA, but all over the western hemisphere.The idea behind this was that if the axiomatic foundations of mathematics were introduced to children, they could "easily" cope with the theorems of the mathematical system later