# $ACA_{0}$

$ACA_{0}$ is a weakened form of second order arithmetic. Its axioms include the axioms of PA together with arithmetic comprehension.

Title $ACA_{0}$ ACA0 2013-03-22 12:57:03 2013-03-22 12:57:03 Henry (455) Henry (455) 4 Henry (455) Definition msc 03F35 ACA ACA0