RT Book, Section T1 Relating function spaces to resourced function spaces. A1 Sánchez Gil, Lidia A1 Hidalgo Herrero, Mercedes A1 Ortega Mallén, Yolanda AB In order to prove the computational adequacy of the (operational)natural semantics for lazy evaluation with respect to a standard denotational semantics, Launchbury defines a resourced denotational semantics. This should be equivalent to the standard one when given infinite resources, but this fact cannot be so directly established, because each semantics produces values in a different domain. The values obtained by the standard semantics belong to the usual lifted function space D = [D → D]⊥, while those produced by the resourced semantics belong to [C → E] where E satisfies the equation E = [[C → E] → [C → E]]⊥ and C (the domain of resources) is a countable chain domain defined as the least solution of the domain equation C = C⊥.We propose a way to relate functional values in the standardlifted function space to functional values in the corresponding resourced function space. We first construct the initial solution for the domain equation E = [[C → E] →[C → E]]⊥ following Abramsky’s construction of the initialsolution of D = [D → D]⊥. Then we define a “similarity”relation between values in the constructed domain and valuesin the standard lifted function space. This relation isinspired by Abramsky’s applicative bisimulation.Finally we prove the desired equivalence between the standard denotational semantics and the resourced semantics for the lazy λ-calculus. PB ACM SN 978-1-4503-0113-8 YR 2001 FD 2001 LK https://hdl.handle.net/20.500.14352/60584 UL https://hdl.handle.net/20.500.14352/60584 LA eng NO Comunidad de Madrid NO Ministerio de Ciencia e Innovación (MICINN) NO Ministerio de Educación DS Docta Complutense RD 9 abr 2025