Ruby and Gauche(Scheme)'s equal operators

gistfile1.txt

ruby 2.0.0p353
    $ irb
    irb(main):001:0> a = "abc"
    => "abc"
    irb(main):002:0> b = "abc"
    => "abc"
    irb(main):003:0> a == b
    => true
    irb(main):004:0> a === b
    => true
    irb(main):005:0> a.equal? b
    => false
    irb(main):006:0> a = :abc
    => :abc
    irb(main):007:0> b = :abc
    => :abc
    irb(main):008:0> a == b
    => true
    irb(main):009:0> a === b
    => true
    irb(main):010:0> a.equal? b
    => true
    irb(main):011:0> quit

Gauche scheme shell, version 0.9.3.3
    $ gosh
    gosh> (define a "abc")
    a
    gosh> (define b "abc")
    b
    gosh> (eq? a b)
    #f
    gosh> (eqv? a b)
    #f
    gosh> (equal? a b)
    #t
    gosh> (define a :abc)
    a
    gosh> (define b :abc)
    b
    gosh> (eq? a b)
    #t
    gosh> (eqv? a b)
    #t
    gosh> (equal? a b)
    #t
    gosh>