an class="alectryon-sentence"><input class="alectryon-toggle" id="literate-lean3-lean-chke" style="display: none" type="checkbox"><label class="alectryon-input" for="literate-lean3-lean-chke">apply and.intro,</label><small class="alectryon-output"><div><div class="alectryon-goals"><blockquote class="alectryon-goal"><div class="goal-hyps"><span><var>p, q, r</var><span class="hyp-type"><b>: </b><span><span class="kt">Prop</span></span></span></span><br><span><var>H</var><span class="hyp-type"><b>: </b><span>q