Creating variables based on conditions with other variables

Hello all,

I am quite new to azure devops and I am struggling with understanding why my approaches to do something in the pipelines doesn't work.

Starting from a template, I have such a piece of code in it, to which I will pass variables:

steps:
  - ${{ if gt(length(parameters.artifactoryUrl), 0) }}:
    - bash: |
        <doSomeWorkHere>
      displayName: Do some work only if the URL is provided

Then in the pipeline everything starts from variables definition like so:

variables:
  - name: isRelease
    value: eq(variables['Build.SourceBranch'], 'refs/heads/master')
  - name: isSnapshot
    value: eq(variables['Build.SourceBranch'], 'refs/heads/develop')
  # set artifactory url to stable if release, to stage if snapshot or else to empty (no publish to artifactory)
  - name: artifactoryUrl
    ${{ if and( and( eq(variables['Build.SourceBranch'], 'refs/heads/master'), ne(variables['Build.Reason'], 'Schedule')), not( and ( eq(variables['Build.SourceBranch'], 'refs/heads/develop'), ne(variables['Build.Reason'], 'Schedule')))) }}:
      value: 'someURL1'
    ${{ if and( not( and ( eq(variables['Build.SourceBranch'], 'refs/heads/master'), ne(variables['Build.Reason'], 'Schedule')) ), and ( eq(variables['Build.SourceBranch'], 'refs/heads/develop'), ne(variables['Build.Reason'], 'Schedule')) ) }}:
      value: 'someURL2'
    ${{ if and( not( and ( eq(variables['Build.SourceBranch'], 'refs/heads/master'), ne(variables['Build.Reason'], 'Schedule')) ), not ( and ( eq(variables['Build.SourceBranch'], 'refs/heads/develop'), ne(variables['Build.Reason'], 'Schedule')) ) ) }}:
      value: ''

The value of artifactoryUrl is passed into the template mentioned above. This actually works. But it looks quite unreadable and there are some duplications. So I made my attemp to simplify it. Instead of checking the same thing as in the previous variables definitions, I tried to reuse those new variables in another conditional expressions like so:

variables:
  - name: isRelease
    value: eq(variables['Build.SourceBranch'], 'refs/heads/master')
  - name: isSnapshot
    value: eq(variables['Build.SourceBranch'], 'refs/heads/develop')
  # set artifactory url to stable if release, to stage if snapshot or else to empty (no publish to artifactory)
  - name: artifactoryUrl
    ${{ if and(eq(variables['isRelease'], true), ne(variables['Build.Reason'], 'Schedule')) }}:
      value: 'someUrl1'
    ${{ if and(eq(variables['isSnapshot'], true), ne(variables['Build.Reason'], 'Schedule')) }}:
      value: 'someUrl2'
    ${{ if or(and(eq(variables['isRelease'], false), eq(variables['isSnapshot'], false)), eq(variables['Build.Reason'], 'Schedule')) }}:
      value: ''

Why referring to the previously created variables doens't work? I already tried to use in those conditions different types of variables (macro, compile-time, run-time) and nothing worked for me. What I am missing?

# Oh forgot to mention, we use older Azure Devops instance, so "else", "elseif" is not recognized.