test_gamma = ->
run_test [
"Gamma(a)",
# "float(gamma(10))",
# "362880",
"Gamma(x+1)",
"x*Gamma(x)",
"Gamma(1/2)",
"pi^(1/2)",
"Gamma(x-1)-Gamma(x)/(-1+x)",
"0",
"Gamma(-x)",
"-pi/(x*Gamma(x)*sin(pi*x))",
]