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+GMP integration for SBCL
+This contrib enables the use of bignum computation routines from the
+GMP library for SBCL internal bignum calculations.
+Some functions can be transparently replaced within SBCL, namely:
+ - sb-bignum:multiply-bignum
+ - sb-bignum:bignum-truncate
+ - sb-bignum:bignum-gcd
+ - sb-kernel::two-arg-lcm
+ - cl:isqrt
+and for making use of the GMP rational arithmetic:
+ - sb-kernel::two-arg-+
+ - sb-kernel::two-arg--
+ - sb-kernel::two-arg-*
+ - sb-kernel::two-arg-/
+Most of the other SBCL bignum routines rely on these functions for the
+heavy computational lifting.
+However, SB-GMP also provides easy and transparent access to several
+other functions of the GMP library and may be able to replace other
+parts of the SBCL bignum machinery in the future. Refer to the GMP
+documentation for the respective function specification.
+The transparent SBCL integration is automatically activated by loading
+SB-GMP.  Some care is taken to behave correctly across core saves and
+loads; however, if this does not work correctly, `SB-GMP:UNLOAD-GMP`
+and `SB-GMP:LOAD-GMP` can be called to explicitly unload and reload
+libgmp and uninstall/reinstall the hooks.  The hooks can also be
+directly uninstalled and installed with `SB-GMP:UNINSTALL-GMP-FUNS`
+and `SB-GMP:INSTALL-GMP-FUNS`.  However, in most cases, binding
+`SB-GMP:*GMP-DISABLED*` to `T` should suffice.