 <span class="hljs-selector-tag">b</span> <span class="hljs-selector-tag">a</span> )

parallelogram = 
    (<span class="hljs-selector-tag">a</span>: Line) ⇒ (<span class="hljs-selector-tag">b</span>: Line) ⇒ (c: Line) ⇒ (d: Line) ⇒ 
    (<span class="hljs-selector-tag">p</span>: parallel <span class="hljs-selector-tag">a</span> b) ⇒ (<span class="hljs-selector-tag">q</span>: parallel c d) ⇒ (r: !parallel <span class="hljs-selector-tag">a</span> d) ⇒
    parallelAxiom d <span class="hljs-selec