tcfail102.hs:1:14: warning:
-XDatatypeContexts is deprecated: It was widely considered a misfeature, and has been removed from the Haskell language.
tcfail102.hs:9:15: error:
• Could not deduce (Integral (Ratio a)) arising from a use of ‘p’
from the context: Integral a
bound by the type signature for:
f :: Integral a => P (Ratio a) -> P (Ratio a)
at tcfail102.hs:8:1-45
• In the ‘p’ field of a record
In the expression: x {p = p x}
In an equation for ‘f’: f x = x {p = p x}