Core size, , and relative coreness, , versus the cost, θ. (a) A decay in the size of the core in regime B for increasing cost is shown. Core size increases again abruptly in the transition between regimes B and C as the pruning mechanism slows down. (b) Illuminates upon the comparison of the relative coreness of the core between a fully connected network in regime A and a core–periphery observed in regime B. The insets of both figures are blow-ups of regime B. The core of the network in regime B has a much lower coreness, which decays continuously with increasing cost until the network becomes a tree. Data are averages over 100 realizations.