Cannot parse "serverless.yaml": missed comma between flow collection entries

Hey,

I’m trying to add a condition for the Resources part of not equals and I’m receiving an error.

resources:
  Conditions:
    IsNotDev: !Not [ !Equals [ ${sls:stage}, dev ]]

What am I doing wrong?

By this way, this way does work -

resources:
  Conditions:
#    IsNotDev: !Not [ !Equals [ ${sls:stage}, dev ]]
    IsNotDev:
      Fn::Not:
        - Fn::Equals:
          - ${sls:stage}
          - dev

Thanks