- name: test with_nested
  set_fact: "{{ item.0 + item.1 }}=x"
  with_nested:
    - [ 'a', 'b' ]
    - [ 'c', 'd' ]

- debug: var=ac
- debug: var=ad
- debug: var=bc
- debug: var=bd

- name: verify with_nested results
  assert:
    that:
        - "ac == 'x'"
        - "ad == 'x'"
        - "bc == 'x'"
        - "bd == 'x'"