We start with a basis of simple roots 𝛥 of 𝛷. Then we apply all possible elementary transformations and add the resulting boldsymbol 𝜋-systems to the list. Of course, if 𝛤 is a boldsymbol 𝜋-system, and 𝛤' is a boldsymbol 𝜋-system obtained from it by an elementary transformation and the diagrams of 𝛤 and 𝛤' are the same, the root subsystems they span are the same, and therefore we do not add 𝛤'.

You must be a popular cow-orker.

The rurban community offers greater possibilities of social stratification than does the open country community.

Mr. Henderson's chief trouble seems to be that he cannot forget his old shiftiness of views and his pendulum-like swingings between Liberalism and Independent Labourism […]