{{#if: {{ifequal|{{{1}}}|táo|{{{2}}}|cam|{{{3}}}|lê}}|Yes|No}} round fruits present".
-- returns true if any pair match so will build the string "Yes round fruits present" -- returns false if none match so will build the string: "No round fruits present"
{{#if: {{#if: {{ifequal|{{{SITENAME}}}|Wikiversity| {{{PAGENAME}}}|Aircraft| {{{SITENAME}}}|Wikimedia commons}}||No}} |outer if's then branch...|outer if's else branch...}} ... inverts the test so tests a condition... with an "inverted result". --Assuming sites are either Wikiversity or Mediawiki commons returns a null string as seen by the second if, which then returns the Null string to the first if... which will expand the specified else condition "outer if's else branch...".