def res(n):
"""Primitive recursive specification:
res(0) = (.)
res(n+1) = res res head(n) o..o(.) eo
"""
if n == 0:
return Resolution.fromString("(.)")
else:
return Resolution(Resolution(head(n-1), Resolution.fromString("o"*(n+1)+"(.)")), Resolution.fromString("eo"))
def head(n):
"""Primitive recursive specification:
head(0) = res ee oeoe(.)
head(n+1) = res head(n) o..oe(.)
"""
if n == 0:
return Resolution.fromString("[ee|oeoe(.)]")
else:
return Resolution(head(n-1), Path.fromString("o"*(n+1) + "e(.)"))