"ytype"
"xtype"
varType
nil
cons
cons
nil
cons
"y"
"xtype"
varType
var
"z"
"xtype"
varType
var
varTerm
nil
cons
cons
nil
cons
nil
cons
cons
"y"
"ytype"
varType
var
"c"
const
"bool"
typeOp
nil
opType
1
def
constTerm
absTerm
"a"
const
1
remove
constTerm
appTerm
assume
subst