<?xml version='1.0' encoding='UTF-8'?>
<AST>
  <HeaderNode startPos="1,1,0" endPos="9,1,220">
    <VariableTable startPos="0,0,0" endPos="0,0,0">
      <NameSlot slot="0" name="in1" startPos="0,0,0" endPos="0,0,0"/>
      <NameSlot slot="1" name="in0" startPos="0,0,0" endPos="0,0,0"/>
      <NameSlot slot="2" name="empty" startPos="2,11,57" endPos="2,16,62"/>
      <NameSlot slot="3" name="a" startPos="0,0,0" endPos="0,0,0"/>
      <NameSlot slot="4" name="head" startPos="2,31,77" endPos="2,35,81"/>
      <NameSlot slot="5" name="collect" startPos="0,0,0" endPos="0,0,0"/>
      <NameSlot slot="6" name="f" startPos="1,5,4" endPos="1,6,5"/>
    </VariableTable>
    <InputDirective startPos="0,0,0" endPos="0,0,0">
      <NameSlot slot="0" name="in1" startPos="0,0,0" endPos="0,0,0"/>
    </InputDirective>
    <InputDirective startPos="0,0,0" endPos="0,0,0">
      <NameSlot slot="1" name="in0" startPos="0,0,0" endPos="0,0,0"/>
    </InputDirective>
    <FunctionDirective startPos="1,1,0" endPos="8,40,219">
      <NameSlot slot="6" name="f" startPos="1,5,4" endPos="1,6,5"/>
      <FunctionNode startPos="0,0,0" endPos="0,0,0">
        <FunctionParameterNode materialize="true" startPos="1,7,6" endPos="1,23,22">
          <NameSlot slot="3" name="a" startPos="1,7,6" endPos="1,8,7"/>
          <TypeNode startPos="1,10,9" endPos="1,23,22"/>
        </FunctionParameterNode>
        <FunctionParameterNode materialize="true" startPos="1,25,24" endPos="1,44,43">
          <NameSlot slot="5" name="collect" startPos="1,25,24" endPos="1,32,31"/>
          <TypeNode startPos="1,33,32" endPos="1,39,38"/>
        </FunctionParameterNode>
        <TailRecFunctionBodyNode startPos="0,0,0" endPos="0,0,0">
          <UsingNode startPos="0,0,0" endPos="0,0,0">
            <VarDirective startPos="0,0,0" endPos="0,0,0">
              <NameSlot slot="2" name="empty" startPos="2,11,57" endPos="2,16,62"/>
              <FunctionCallNode startPos="2,19,65" endPos="2,29,75"/>
            </VarDirective>
            <VarDirective startPos="0,0,0" endPos="0,0,0">
              <NameSlot slot="4" name="head" startPos="2,31,77" endPos="2,35,81"/>
              <NullSafeNode startPos="2,38,84" endPos="2,41,87">
                <BinaryOpNode startPos="2,38,84" endPos="2,41,87"/>
              </NullSafeNode>
            </VarDirective>
            <IfNode startPos="0,0,0" endPos="0,0,0">
              <VariableReferenceNode startPos="4,9,112" endPos="4,16,119"/>
              <VariableReferenceNode startPos="3,8,97" endPos="3,13,102"/>
              <IfNode startPos="0,0,0" endPos="0,0,0">
                <InlineTailRecFunctionCall startPos="0,0,0" endPos="0,0,0">
                  <VarDirective startPos="0,0,0" endPos="0,0,0">
                    <NameSlot slot="3" name="a" startPos="1,7,6" endPos="1,8,7"/>
                    <NullSafeNode startPos="6,11,159" endPos="6,20,168">
                      <BinaryOpNode startPos="6,11,159" endPos="6,20,168"/>
                    </NullSafeNode>
                  </VarDirective>
                  <VarDirective startPos="0,0,0" endPos="0,0,0">
                    <NameSlot slot="5" name="collect" startPos="1,25,24" endPos="1,32,31"/>
                    <StringNode startPos="1,42,41" endPos="1,44,43"></StringNode>
                  </VarDirective>
                </InlineTailRecFunctionCall>
                <BinaryOpNode startPos="5,13,132" endPos="5,28,147"/>
                <InlineTailRecFunctionCall startPos="0,0,0" endPos="0,0,0">
                  <VarDirective startPos="0,0,0" endPos="0,0,0">
                    <NameSlot slot="3" name="a" startPos="1,7,6" endPos="1,8,7"/>
                    <NullSafeNode startPos="8,11,190" endPos="8,20,199">
                      <BinaryOpNode startPos="8,11,190" endPos="8,20,199"/>
                    </NullSafeNode>
                  </VarDirective>
                  <VarDirective startPos="0,0,0" endPos="0,0,0">
                    <NameSlot slot="5" name="collect" startPos="1,25,24" endPos="1,32,31"/>
                    <FunctionCallNode startPos="8,24,203" endPos="8,39,218"/>
                  </VarDirective>
                </InlineTailRecFunctionCall>
              </IfNode>
            </IfNode>
          </UsingNode>
        </TailRecFunctionBodyNode>
      </FunctionNode>
    </FunctionDirective>
  </HeaderNode>
  <FunctionCallNode startPos="10,1,224" endPos="10,37,260"/>
</AST>