tree-equal

(tree-equal tree-1 tree-2 &key test test-not)

Returns t when the two cons trees have the same shape and every pair of corresponding leaves matches. A cons only ever matches a cons, so a tree and a leaf in the same position differ. Leaves compare with :test (default eql) or, with :test-not, match exactly where that function answers false. Note that two strings with the same characters are already eql here, unlike in most Common Lisps.