Install cl-bordeaux-threads by entering the following commands in the terminal:
sudo apt update sudo apt install cl-bordeaux-threads
Portable shared-state concurrency for Common Lisp
BORDEAUX-THREADS is a proposed standard for a minimal MP/Threading interface. . It essentially provides a compatibility layer for multi-threading accross multiple CL implementations. . Some parts of it's implementation-specific code can also be implemented in a Lisp that does not support multiple threads, so that thread-safe code can be compiled on both multithread and single-thread implementations without need of conditionals.