error[E0412]: cannot find type `PhantomData` in this scope
  --> $DIR/issue-77919.rs:9:9
   |
LL |     _n: PhantomData,
   |         ^^^^^^^^^^^ not found in this scope
   |
help: consider importing this struct
   |
LL | use std::marker::PhantomData;
   |

error[E0412]: cannot find type `VAL` in this scope
  --> $DIR/issue-77919.rs:11:63
   |
LL | impl<N, M> TypeVal<usize> for Multiply<N, M> where N: TypeVal<VAL> {}
   |          -                                                    ^^^ not found in this scope
   |          |
   |          help: you might be missing a type parameter: `, VAL`

error[E0283]: type annotations needed
  --> $DIR/issue-77919.rs:11:12
   |
LL | impl<N, M> TypeVal<usize> for Multiply<N, M> where N: TypeVal<VAL> {}
   |            ^^^^^^^^^^^^^^ cannot infer type for struct `Multiply<N, M>`
   |
   = note: cannot satisfy `Multiply<N, M>: TypeVal<usize>`

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0283, E0412.
For more information about an error, try `rustc --explain E0283`.