le error&gt;) name:string?</td><td>&nbsp;</td></tr>

  <tr><td>Gauche</td><td>(sys-getenv name) =&gt; (or string? false) name:string?</td><td>(sys-environ)</td></tr>
  <tr><td>Guile</td><td>(getenv name) =&gt; (or string? false) name:string?</td><td>&nbsp;</td></tr>
  <tr><td>PLT</td><td>(getenv name) =&gt; (or string? false) name:string?</td><td>&nbsp;</td></tr>
  <tr><td>MIT/GNU Scheme</td><td>(get-environment-variable name) =&gt; (or string? false) name:string?</td><td>&nbsp;</td></tr>
  <tr><td>Scheme48