We prove two of the inequalities needed to obtain the following result on the ordinal values of ptykes of type 2, which are definable in Gödel'sT. LetG be a dilator satisfyingG(0)=ω, ∀x:G(x)≧x, and ∀η<Ω:G(η)<Ω, and letg be the ordinal function induced byG. Then sup{A(G)∣A ptyx of type 2 definable in Gödel'sT} = sup{x∣x is∑ 1 g -definable without parameters provably in KP(G)} =J (2 +Id) g (ω) (0) = the “Bachmann-Howard ordinal relative tog”. KP(G) is obtained from Kripke-Platek set theory (...) without urelements KP by adjoining a two-place relation symbolG and axioms expressing thatG is the graph of a total function from ordinals to ordinals.J D g is an iteration hierarchy defined relative tog by primitive recursion on dilators. (2 +Id)(ω) is the dilator $$\mathop {\sup }\limits_{n< \omega } (\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{2} + Id)_{(n)} $$ with (2 +Id)(0)≔1 and $$(\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{2} + Id)_{(n + 1)} : = (\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{2} + Id)^{(2 + Id)_{(n)} } $$ . The “Bachmann-Howard ordinal relative tog” is the closure ordinal of a Bachmann hierarchy of lengthε Ω + 1, which is built on an iteration ofg as initial function.For the caseG=(1+Id)·ω, KP(G) is equivalent to Jäger's theory KPu, and the “Bachmann-Howard ordinal relative tog” is the usual “Bachmann-Howard ordinal”. For the caseG=Ξ1 KP(G) can be replaced by Jäger's theory KPi, andg can be replaced by the functionλx. x +.x + is the successor admissible ofx, andΞ 1 is the sum of all recursive dilators in an arbitrary enumeration. (shrink)