home	news	documentation	specification		implementation
foreword	milestones	version 2	version 2	(background - core - applications)	library	(static LDDL directory)
citations	visibility	version 1	version 1	(static HELM directory)	helena

Informal description: ""

{λ[sigma:Set] .​ λ[tau:Set] .​ λ[upsilon:Set] .​ λ[f:Π[x:sigma] .​ tau] .​ λ[g:Π[x:tau] .​ upsilon] .​ λ[sf:{(f) .​ (tau) .​ (sigma)} .​ surjective ] .​ λ[sg:{(g) .​ (upsilon) .​ (tau)} .​ surjective ] .​ λ[u:upsilon] .​ λ[t:tau] .​ λ[i:{((t) .​ g) .​ (u) .​ (upsilon)} .​ is ]} .​ <{(t) .​ (f) .​ (tau) .​ (sigma)} .​ image > .​ (t) .​ sf

Validation parameters: sort hierarchy = "Z2", kernel options = ""