Package: libc6-amd64
Architecture: i386
Section: libs
Priority: standard
Depends: libc6 (= ${binary:Version}), ${misc:Depends}
Conflicts: amd64-libs (<= 1.2)
Description: GNU C Library: 64bit Shared libraries for AMD64
 This package includes shared versions of the standard C library and the
 standard math library, as well as many others. This is the 64bit version
 of the library, meant for AMD64 systems.

Package: libc6-dev-amd64
Architecture: i386
Section: libdevel
Priority: optional
Depends: libc6-amd64 (= ${binary:Version}), libc6-dev (= ${binary:Version}), ${misc:Depends}
Recommends: gcc-multilib
Replaces: amd64-libs-dev (<= 1.2)
Provides: lib64c-dev
Description: GNU C Library: 64bit Development Libraries for AMD64
 Contains the symlinks and object files needed to compile and link programs
 which use the standard C library. This is the 64bit version of the
 library, meant for AMD64 systems.