diff --git a/packages/ludic.ui/class.ludic b/packages/ludic.ui/class.ludic
index c5db0c95..2294a31f 100644
--- a/packages/ludic.ui/class.ludic
+++ b/packages/ludic.ui/class.ludic
@@ -40,7 +40,9 @@ function uc_load(ui_st: mut UiState, k: UiClass) -> void {
   if k.lss != "" { lss_text(ui_st, f, k.lss) }
   f.sheet = sheet_of(f)
   tp_lines(ui_st, k.xml)
-  let root = tpl_read(ui_st, Xml.parse(k.xml), k.xml_path)
+  let doc = Xml.parse(k.xml)
+  let root = tpl_read(ui_st, doc, k.xml_path)
+  Xml.free(doc)                        # the template keeps the tree's strings, never its nodes
   k.sheet = f.sheet
   lib_link(ui_st, f, root)
   k.root = root
diff --git a/packages/ludic.ui/expr_parse.ludic b/packages/ludic.ui/expr_parse.ludic
index f14f6f12..1a574eb3 100644
--- a/packages/ludic.ui/expr_parse.ludic
+++ b/packages/ludic.ui/expr_parse.ludic
@@ -48,10 +48,13 @@ function px_bin(op: string, a: UiExpr, b: UiExpr) -> UiExpr {
 }
 function px_cmp(r: UiRd) -> UiExpr {
   let a = px_sum(r)
-  let ops = ["==", "!=", "<=", ">=", "<", ">"]
-  for k in 0 .. len(ops) {
-    if rd_op(r, ops[k]) { return px_bin(ops[k], a, px_sum(r)) }
-  }
+  # literals, longest first: a list of them was made on every call
+  if rd_op(r, "==") { return px_bin("==", a, px_sum(r)) }
+  if rd_op(r, "!=") { return px_bin("!=", a, px_sum(r)) }
+  if rd_op(r, "<=") { return px_bin("<=", a, px_sum(r)) }
+  if rd_op(r, ">=") { return px_bin(">=", a, px_sum(r)) }
+  if rd_op(r, "<") { return px_bin("<", a, px_sum(r)) }
+  if rd_op(r, ">") { return px_bin(">", a, px_sum(r)) }
   return a
 }
 function px_sum(r: UiRd) -> UiExpr {
diff --git a/packages/ludic.ui/expr_prim.ludic b/packages/ludic.ui/expr_prim.ludic
index c95a36a3..41e05067 100644
--- a/packages/ludic.ui/expr_prim.ludic
+++ b/packages/ludic.ui/expr_prim.ludic
@@ -62,6 +62,7 @@ function ex_parse(src: string, err: []string) -> UiExpr {
   rd_ws(r)
   if r.err == "" and r.i < len(r.s) { rd_fail(r, "the end") }
   if r.err != "" { push(err, r.err) }
+  unsafe { free(r) }                   # the reader only: what the expression keeps is copied out
   return e
 }
 # text with {holes}: a literal when it has none, the expression itself when it is one hole and
diff --git a/packages/ludic.ui/lib.ludic b/packages/ludic.ui/lib.ludic
index 1588fc0c..c05f4302 100644
--- a/packages/ludic.ui/lib.ludic
+++ b/packages/ludic.ui/lib.ludic
@@ -39,7 +39,9 @@ function lib_read(ui_st: mut UiState, src: string, path: string) -> UiFile {
   let f = lib_new(ui_st, path)
   f.src = src
   tp_lines(ui_st, src)
-  let root = tpl_read(ui_st, Xml.parse(src), path)
+  let doc = Xml.parse(src)
+  let root = tpl_read(ui_st, doc, path)
+  Xml.free(doc)                        # the template keeps the tree's strings, never its nodes
   var tops = root.kids
   if root.tag != "ui" { tops = [root] }
   for i in 0 .. len(tops) { lib_top(ui_st, f, tops[i]) }
diff --git a/packages/ludic.ui/select.ludic b/packages/ludic.ui/select.ludic
index 63d44029..7672f296 100644
--- a/packages/ludic.ui/select.ludic
+++ b/packages/ludic.ui/select.ludic
@@ -51,6 +51,8 @@ function sel_parse(src: string, err: []string) -> UiSel {
     comb = 0
   }
   if r.err != "" { push(err, r.err) }
+  unsafe { free(r) }                   # the reader only: every name read from it is a copy
+  @alloc_ok("only when a template is wrong: a broken screen, never a working one")
   if cur == null { push(err, `"{src}" selects nothing`) }
   return cur
 }
diff --git a/packages/ludic.ui/style_rule.ludic b/packages/ludic.ui/style_rule.ludic
index 4243927c..69b07d20 100644
--- a/packages/ludic.ui/style_rule.ludic
+++ b/packages/ludic.ui/style_rule.ludic
@@ -10,7 +10,10 @@ function lss_rule(f: UiFile, sels: string, body: string, err: []string) -> void
       free(each[i])
     }
   }
-  unsafe { free(each) }
+  unsafe {
+    free(each)
+    free(decls)                        # the holder only: each rule keeps its keys and values lists
+  }
 }
 function lss_rule_add(f: UiFile, decls: UiRule, sel: string, err: []string) -> void {
   let r = new UiRule
diff --git a/runtime/native/namespaces.ludic b/runtime/native/namespaces.ludic
index 60d17447..2b0fc065 100644
--- a/runtime/native/namespaces.ludic
+++ b/runtime/native/namespaces.ludic
@@ -495,6 +495,7 @@ namespace Json {
 }
 namespace Xml {
   alias parse(text) = xml_parse
+  alias free(node) = xml_free          # the tree's records and lists; its strings are kept
   alias tag(node) = xml_tag
   alias text(node) = xml_text
   alias attr(node, key) = xml_attr
diff --git a/runtime/native/xml.ludic b/runtime/native/xml.ludic
index f82ec980..b59400d4 100644
--- a/runtime/native/xml.ludic
+++ b/runtime/native/xml.ludic
@@ -322,8 +322,26 @@ function xml_parse(rt_xml_st: mut RtXmlState, s: pointer) -> Xml {
     if p.i >= p.n { break }
     if p.s[p.i] == '<' {                                   # '<'
       if xp_skip_misc(p) { }                              # prolog / comment / doctype
-      else { return xp_element(rt_xml_st, p) }
+      else {
+        let root = xp_element(rt_xml_st, p)
+        free(p)
+        return root
+      }
     } else { p.i += 1 }
   }
+  free(p)
   return xml_new("")
 }
+
+# the tree's records and lists given back once a reader has built what it keeps from it; its
+# strings (tags, text, names, values) are not, since what was built may hold them. Every element
+# is in its parent's `mixed`, with the runs of text
+function xml_free(n: Xml) -> void {
+  if n == null { return }
+  for i in 0 .. len(n.mixed) { xml_free(n.mixed[i]) }
+  free(n.akeys)
+  free(n.avals)
+  free(n.kids)
+  free(n.mixed)
+  free(n)
+}