load_thy/after_load: explicit check of parent theories, which might have failed to join proofs -- avoid uninformative crash via Graph.UNDEF;
header {* Install quickcheck of SML code generator *}
theory SML_Quickcheck
imports Main
begin
setup {*
Inductive_Codegen.quickcheck_setup #>
Quickcheck.add_generator ("SML", Codegen.test_term)
*}
end