HTML RESULT 
{set $abc = 10}

{content 'myContent'}
  {$abc} <br>
{/content}
{increment $abc} {myContent}
{increment $abc} {myContent}
{increment $abc} {myContent}
11
12
13 
{set $abc = 10}

{content}
  {$abc} <br>
{/content 'myContent'}
{increment $abc} {myContent}
{increment $abc} {myContent}
{increment $abc} {myContent}
10
10
10