Properties of B-Trees

1. Node x

n(x) = #keys stored here
leaf(x) = true if leaf node

$$k_1 \;\leq\; key_1(x) \;\leq\; k_2 \;\leq\; key_2(x) \;\leq\; ... \;\leq\; key_{n(x)}(x) \;\leq\; k_{n(x)+1}$$