Martin Berger questions

• Why can I prove ⟦ ( ∃ x. P ) ∧ ( ∃ x. Q ) ⟧ ⟹ ∃ x. (P ∧ Q)?
• Reductions in the Erlang BEAM machine
• Scala's monadic chaining of Try
• Running multiple shell commands with wildcards
• Scala constructor abstraction
• Typechecking inside quasi-quotes in Template Haskell

Martin Berger answers